diff --git a/.gitignore b/.gitignore
index e5d3578f1..70f7a9c79 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,4 +1,6 @@
 build/dist
+build/size
+build/build/.sizecache.json
 docs
 .project
 *~
diff --git a/build/build.xml b/build/build.xml
index 154e7f60c..664982565 100644
--- a/build/build.xml
+++ b/build/build.xml
@@ -9,13 +9,13 @@
 -->
 
 <project name="jquery-ui" default="deploy-release" basedir=".">
-	
+
 	<taskdef resource="net/sf/antcontrib/antcontrib.properties">
 		<classpath>
 			<pathelement location="build/ant-contrib-0.6.jar"/>
 		</classpath>
 	</taskdef>
-	
+
 	<property file="ant.properties" />
 
 	<loadfile failonerror="no" srcFile="../version.txt" property="release.version">
@@ -32,6 +32,7 @@
 	<property name="docs.dir" value="${dist.dir}/docs/" />
 
 	<property name="min.dir" value="${dist.dir}/ui/minified" />
+	<property name="size.dir" value="size" />
 
 	<property name="concatenated" value="jquery-ui" />
 	<property name="concatenated.i18n" value="jquery-ui-i18n" />
@@ -41,25 +42,25 @@
 
 	<property description="Google Closure" name="closure-jar" value="${build.dir}/google-compiler-20110320.jar" />
 	<property description="YUI Compressor" name="yuicompressor-jar" value="${build.dir}/yuicompressor-2.4.2.jar" />
-	
+
 	<target name="deploy-release" depends="clean, docs-download, copy, minify, replace-version, prepend-header, zip" description="Release builder">
 	</target>
-	
+
 	<target name="replace-version">
 		<replaceregexp match="@VERSION" replace="${release.version}" flags="g" byline="true">
-		    <fileset dir="${dist.dir}/ui/" includes="*.js"/>
+			<fileset dir="${dist.dir}/ui/" includes="*.js"/>
 			<fileset dir="${dist.dir}/ui/minified/" includes="*.js"/>
 			<fileset dir="${dist.dir}/themes/" includes="**/*.css"/>
 		</replaceregexp>
 		<echo message="Replaced all @VERSION to ${release.version}." />
 	</target>
-	
+
 	<target name="prepend-header">
 		<copy todir="${dist.dir}/headers/">
 			<fileset dir="${dist.dir}/ui/" includes="*.js" />
 		</copy>
 		<replaceregexp match="^(\/\*.*?\*\/\s).+" replace="\1" flags="s">
-		    <fileset dir="${dist.dir}/headers/" includes="*.js"/>
+				<fileset dir="${dist.dir}/headers/" includes="*.js"/>
 		</replaceregexp>
 		<for param="file">
 			<path><fileset dir="${min.dir}/" includes="*.js" /></path>
@@ -74,12 +75,12 @@
 		<copy todir="${min.dir}" overwrite="true">
 			<fileset dir="${dist.dir}/ui-headered/" includes="*.js" />
 		</copy>
-		
+
 		<copy todir="${dist.dir}/headers/">
 			<fileset dir="${dist.dir}/themes/base" includes="*.css" />
 		</copy>
 		<replaceregexp match="^(\/\*.*?\*\/\s).+" replace="\1" flags="s">
-		    <fileset dir="${dist.dir}/headers/" includes="*.css"/>
+				<fileset dir="${dist.dir}/headers/" includes="*.css"/>
 		</replaceregexp>
 		<for param="file">
 			<path><fileset dir="${dist.dir}/themes/base/minified" includes="*.css" /></path>
@@ -94,14 +95,14 @@
 		<copy todir="${dist.dir}/themes/base/minified" overwrite="true">
 			<fileset dir="${dist.dir}/ui-headered/" includes="*.css" />
 		</copy>
-		
+
 		<!-- once more for the i18n files -->
 		<!-- need to clean up headers in those files first
 		<copy todir="${dist.dir}/headers/i18n/">
 			<fileset dir="${dist.dir}/ui/i18n/" includes="*.js" />
 		</copy>
 		<replaceregexp match="^(\/\*.*?\*\/\s).+" replace="\1" flags="s">
-		    <fileset dir="${dist.dir}/headers/i18n/" includes="*.js"/>
+				<fileset dir="${dist.dir}/headers/i18n/" includes="*.js"/>
 		</replaceregexp>
 		<for param="file">
 			<path><fileset dir="${min.dir}/i18n/" includes="*.js" /></path>
@@ -161,61 +162,61 @@
 		<mkdir dir="${min.dir}/i18n/" />
 		<mkdir dir="${dist.dir}/themes/base/minified" />
 
-        <parallel threadsperprocessor="1">
+				<parallel threadsperprocessor="1">
 
-            <apply executable="java" parallel="false">
-                <fileset dir="${dist.dir}/ui" includes="*.js" />
-                <arg line="-jar" />
-                <arg path="${closure-jar}" />
-                <arg value="--warning_level" />
-                <arg value="QUIET" />
-                <arg value="--js_output_file" />
-                <targetfile />
-                <arg value="--js" />
-                <mapper type="glob" from="*.js" to="${min.dir}/*.min.js" />
-            </apply>
+						<apply executable="java" parallel="false">
+								<fileset dir="${dist.dir}/ui" includes="*.js" />
+								<arg line="-jar" />
+								<arg path="${closure-jar}" />
+								<arg value="--warning_level" />
+								<arg value="QUIET" />
+								<arg value="--js_output_file" />
+								<targetfile />
+								<arg value="--js" />
+								<mapper type="glob" from="*.js" to="${min.dir}/*.min.js" />
+						</apply>
 
-            <apply executable="java" parallel="false">
-                <fileset dir="${dist.dir}/ui/i18n" includes="*.js" />
-                <arg line="-jar" />
-                <arg path="${closure-jar}" />
-                <arg value="--warning_level" />
-                <arg value="QUIET" />
-                <arg value="--js_output_file" />
-                <targetfile />
-                <arg value="--js" />
-                <mapper type="glob" from="*.js" to="${min.dir}/i18n/*.min.js" />
-            </apply>
+						<apply executable="java" parallel="false">
+								<fileset dir="${dist.dir}/ui/i18n" includes="*.js" />
+								<arg line="-jar" />
+								<arg path="${closure-jar}" />
+								<arg value="--warning_level" />
+								<arg value="QUIET" />
+								<arg value="--js_output_file" />
+								<targetfile />
+								<arg value="--js" />
+								<mapper type="glob" from="*.js" to="${min.dir}/i18n/*.min.js" />
+						</apply>
 
-            <apply executable="java" parallel="false">
-                <fileset dir="${dist.dir}/themes/base" includes="*.css" />
-                <arg line="-jar" />
-                <arg path="${yuicompressor-jar}" />
-                <arg line="--charset utf-8" />
-                <arg line="-v" />
-                <srcfile />
-                <arg line="-o" />
-                <mapper type="glob" from="*.css" to="${dist.dir}/themes/base/minified/*.min.css" />
-                <targetfile/>
-            </apply>
+						<apply executable="java" parallel="false">
+								<fileset dir="${dist.dir}/themes/base" includes="*.css" />
+								<arg line="-jar" />
+								<arg path="${yuicompressor-jar}" />
+								<arg line="--charset utf-8" />
+								<arg line="-v" />
+								<srcfile />
+								<arg line="-o" />
+								<mapper type="glob" from="*.css" to="${dist.dir}/themes/base/minified/*.min.css" />
+								<targetfile/>
+						</apply>
+
+				</parallel>
 
-        </parallel>
-		
 		<replaceregexp match=".css" replace=".min.css" flags="g">
 			<fileset dir="${dist.dir}/themes/base/minified/">
 				<include name="*.base.min.css"/>
 				<include name="*.all.min.css"/>
 			</fileset>
 		</replaceregexp>
-		
+
 		<!-- make a copy of all theme images to ensure that relative paths in minified css files work -->
 		<copy todir="${dist.dir}/themes/base/minified/images" >
 			<fileset dir="${ui.dir}/themes/base/images" />
 		</copy>
-		
+
 		<echo message="Minified ui/ built." />
 	</target>
-	
+
 	<target description="Copy needed folders" name="copy">
 		<echo message="Copying files" />
 		<mkdir dir="${dist.dir}" />
@@ -253,67 +254,67 @@
 		</copy>
 		<echo message="Files copied." />
 	</target>
-	
+
 	 <target name="clean">
-	 	<delete dir="dist" />
-    </target>
-	
+		<delete dir="dist" />
+		</target>
+
 	<target name="docs-download">
 		<mkdir dir="${docs.dir}" />
 		<property name="url" value="http://docs.jquery.com/action/render/UI/API/${release.version}/" />
 
-        <parallel threadcount="8">
+				<parallel threadcount="8">
 
-            <get src="${url}Draggable" dest="${docs.dir}draggable.html" />
-            <get src="${url}Droppable" dest="${docs.dir}droppable.html" />
-            <get src="${url}Resizable" dest="${docs.dir}resizable.html" />
-            <get src="${url}Selectable" dest="${docs.dir}selectable.html" />
-            <get src="${url}Sortable" dest="${docs.dir}sortable.html" />
+						<get src="${url}Draggable" dest="${docs.dir}draggable.html" />
+						<get src="${url}Droppable" dest="${docs.dir}droppable.html" />
+						<get src="${url}Resizable" dest="${docs.dir}resizable.html" />
+						<get src="${url}Selectable" dest="${docs.dir}selectable.html" />
+						<get src="${url}Sortable" dest="${docs.dir}sortable.html" />
 
-            <get src="${url}Accordion" dest="${docs.dir}accordion.html" />
-            <get src="${url}Autocomplete" dest="${docs.dir}autocomplete.html" />
-            <get src="${url}Button" dest="${docs.dir}button.html" />
-            <get src="${url}Datepicker" dest="${docs.dir}datepicker.html" />
-            <get src="${url}Dialog" dest="${docs.dir}dialog.html" />
-            <get src="${url}Menu" dest="${docs.dir}menu.html" />
-            <get src="${url}Progressbar" dest="${docs.dir}progressbar.html" />
-            <get src="${url}Slider" dest="${docs.dir}slider.html" />
-            <get src="${url}Spinner" dest="${docs.dir}spinner.html" />
-            <get src="${url}Tooltip" dest="${docs.dir}tooltip.html" />
-            <get src="${url}Tabs" dest="${docs.dir}tabs.html" />
+						<get src="${url}Accordion" dest="${docs.dir}accordion.html" />
+						<get src="${url}Autocomplete" dest="${docs.dir}autocomplete.html" />
+						<get src="${url}Button" dest="${docs.dir}button.html" />
+						<get src="${url}Datepicker" dest="${docs.dir}datepicker.html" />
+						<get src="${url}Dialog" dest="${docs.dir}dialog.html" />
+						<get src="${url}Menu" dest="${docs.dir}menu.html" />
+						<get src="${url}Progressbar" dest="${docs.dir}progressbar.html" />
+						<get src="${url}Slider" dest="${docs.dir}slider.html" />
+						<get src="${url}Spinner" dest="${docs.dir}spinner.html" />
+						<get src="${url}Tooltip" dest="${docs.dir}tooltip.html" />
+						<get src="${url}Tabs" dest="${docs.dir}tabs.html" />
 
-            <get src="${url}Position" dest="${docs.dir}position.html" />
+						<get src="${url}Position" dest="${docs.dir}position.html" />
 
-            <get src="http://docs.jquery.com/action/render/UI/Effects/animate" dest="${docs.dir}animate.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/addClass" dest="${docs.dir}addClass.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/effect" dest="${docs.dir}effect.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/hide" dest="${docs.dir}hide.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/removeClass" dest="${docs.dir}removeClass.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/show" dest="${docs.dir}show.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/switchClass" dest="${docs.dir}switchClass.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/toggle" dest="${docs.dir}toggle.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/toggleClass" dest="${docs.dir}toggleClass.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/animate" dest="${docs.dir}animate.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/addClass" dest="${docs.dir}addClass.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/effect" dest="${docs.dir}effect.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/hide" dest="${docs.dir}hide.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/removeClass" dest="${docs.dir}removeClass.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/show" dest="${docs.dir}show.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/switchClass" dest="${docs.dir}switchClass.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/toggle" dest="${docs.dir}toggle.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/toggleClass" dest="${docs.dir}toggleClass.html" />
 
 
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Blind" dest="${docs.dir}effect-blind.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Clip" dest="${docs.dir}effect-clip.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Drop" dest="${docs.dir}effect-drop.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Explode" dest="${docs.dir}effect-explode.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Fade" dest="${docs.dir}effect-fade.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Fold" dest="${docs.dir}effect-fold.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Puff" dest="${docs.dir}effect-puff.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Slide" dest="${docs.dir}effect-slide.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Scale" dest="${docs.dir}effect-scale.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Blind" dest="${docs.dir}effect-blind.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Clip" dest="${docs.dir}effect-clip.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Drop" dest="${docs.dir}effect-drop.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Explode" dest="${docs.dir}effect-explode.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Fade" dest="${docs.dir}effect-fade.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Fold" dest="${docs.dir}effect-fold.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Puff" dest="${docs.dir}effect-puff.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Slide" dest="${docs.dir}effect-slide.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Scale" dest="${docs.dir}effect-scale.html" />
 
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Bounce" dest="${docs.dir}effect-bounce.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Highlight" dest="${docs.dir}effect-highlight.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Pulsate" dest="${docs.dir}effect-pulsate.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Shake" dest="${docs.dir}effect-shake.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Size" dest="${docs.dir}effect-size.html" />
-            <get src="http://docs.jquery.com/action/render/UI/Effects/Transfer" dest="${docs.dir}effect-transfer.html" />
-        </parallel>
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Bounce" dest="${docs.dir}effect-bounce.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Highlight" dest="${docs.dir}effect-highlight.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Pulsate" dest="${docs.dir}effect-pulsate.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Shake" dest="${docs.dir}effect-shake.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Size" dest="${docs.dir}effect-size.html" />
+						<get src="http://docs.jquery.com/action/render/UI/Effects/Transfer" dest="${docs.dir}effect-transfer.html" />
+				</parallel>
 	</target>
-	
+
 	<target name="themes-download">
 		<!-- to create/update query strings for the theme-file, execute this in Firebug on /download page:
 		$("select option[value!=none]").map(function() { $(this).parent().val(this.value).change(); return $(this).parents("form").serialize(); }).get().join(",");
@@ -325,11 +326,11 @@
 			<sequential>
 				<get src="http://ui-dev.jquery.com/download/?@{url}" dest="${zip}" />
 				<unzip src="${zip}"
-				       dest="${dist.dir}themes/">
-				    <patternset>
-				        <include name="development-bundle/themes/**"/>
-				        <exclude name="development-bundle/themes/base/**"/>
-				    </patternset>
+							dest="${dist.dir}themes/">
+						<patternset>
+								<include name="development-bundle/themes/**"/>
+								<exclude name="development-bundle/themes/base/**"/>
+						</patternset>
 					<mapper type="glob" from="development-bundle/themes/*" to="*" />
 				</unzip>
 				<delete file="${zip}" />
@@ -351,15 +352,46 @@
 
 	<target name="whitespace">
 		<replaceregexp match="[\t ]+$" replace="" flags="g" byline="true">
-		    <fileset dir="${src.dir}" includes="*.js"/>
-		    <fileset dir="${src.dir}/i18n/" includes="*.js"/>
+				<fileset dir="${src.dir}" includes="*.js"/>
+				<fileset dir="${src.dir}/i18n/" includes="*.js"/>
 		</replaceregexp>
 		<echo message="All trailing spaces removed." />
 	</target>
-	
+
+	<target name="size" depends="copy, minify, replace-version, prepend-header" description="Report sizes of files">
+		<echo message="Collecting files to size" />
+		<mkdir dir="${size.dir}" />
+		<copy todir="${size.dir}">
+			<fileset dir="${dist.dir}/ui" includes="*.js" />
+			<fileset dir="${dist.dir}/ui/i18n" includes="*.js" />
+			<fileset dir="${dist.dir}/ui/minified" includes="*.js" />
+			<fileset dir="${dist.dir}/ui/minified/i18n" includes="*.js" />
+			<fileset dir="${dist.dir}/themes/base" includes="*.css" />
+			<fileset dir="${dist.dir}/themes/base/minified" includes="*.css" />
+		</copy>
+		<echo message="GZipping Minified" />
+		<parallel threadsperprocessor="2">
+			<apply executable="gzip">
+				<fileset dir="${size.dir}" includes="*.min.js" />
+				<fileset dir="${size.dir}" includes="*.min.css" />
+				<arg value="-c" />
+				<srcfile />
+				<redirector>
+					<outputmapper id="out" type="glob" from="*" to="${size.dir}/*.gz"/>
+				</redirector>
+			</apply>
+		</parallel>
+		<echo message="Comparing file size with previous build" />
+		<exec executable="bash">
+			<arg value="-c" />
+			<arg value="wc -c ${size.dir}/* | `which node nodejs` build/sizer.js" />
+		</exec>
+		<delete dir="${size.dir}" />
+	</target>
+
 	<target name="cdn">
-    	<delete dir="${cdndist.dir}" />
-    	<mkdir dir="${cdndist.dir}" />
+		<delete dir="${cdndist.dir}" />
+		<mkdir dir="${cdndist.dir}" />
 		<copy todir="${cdndist.dir}">
 			<fileset dir=".." includes="AUTHORS.txt, GPL-LICENSE.txt, MIT-LICENSE.txt, version.txt" />
 		</copy>
@@ -378,9 +410,9 @@
 			<fileset dir="${cdndist.dir}" />
 		</checksum>
 		<for param="file">
-    		<path><fileset dir="${cdndist.dir}" includes="**/" excludes="**/*.MD5" /></path>
+				<path><fileset dir="${cdndist.dir}" includes="**/" excludes="**/*.MD5" /></path>
 			<sequential>
-				<!-- @{file} is an absolute path, use that ugly regexes to make it relative --> 
+				<!-- @{file} is an absolute path, use that ugly regexes to make it relative -->
 				<propertyregex override="yes" property="relativepath" input="@{file}" regexp=".+?cdn[\\/](.+)$" replace="\1"/>
 				<propertyregex override="yes" property="relativepath" input="${relativepath}" regexp="\\" replace="/" global="true" />
 				<concat destfile="${cdndist.dir}/MANIFEST" append="yes">${relativepath} </concat>
@@ -394,6 +426,6 @@
 		<zip destfile="${dist.dir}/../${release.filename}-mscdn.zip">
 			<zipfileset dir="dist/${release.filename}-cdn/" />
 		</zip>
-    </target>
+		</target>
 
 </project>
diff --git a/build/build/sizer.js b/build/build/sizer.js
new file mode 100644
index 000000000..3c3e4c428
--- /dev/null
+++ b/build/build/sizer.js
@@ -0,0 +1,35 @@
+var fs = require( "fs" ),
+	stdin = process.openStdin(),
+	rsize = /(\d+).*?(jquery\S+)/g,
+	oldsizes = {},
+	sizes = {};
+
+try {
+	oldsizes = JSON.parse( fs.readFileSync(  __dirname + "/.sizecache.json", "utf8" ) );
+} catch(e) {
+	oldsizes = {};
+};
+
+stdin.on( "data" , function( chunk ) {
+	var match;
+
+	while ( match = rsize.exec( chunk ) ) {
+		sizes[ match[2] ] = parseInt( match[1], 10 );
+	}
+});
+
+function lpad( str, len, chr ) {
+	return ( Array(len+1).join( chr || " ") + str ).substr( -len );
+}
+
+stdin.on( "end", function() {
+	fs.writeFileSync( __dirname + "/.sizecache.json", JSON.stringify( sizes, true ), "utf8" );
+	for ( var key in sizes ) {
+		var diff = oldsizes[ key ] && ( sizes[ key ] - oldsizes[ key ] );
+		if ( diff > 0 ) {
+			diff = "+" + diff;
+		}
+		console.log( "%s %s %s", lpad( sizes[ key ], 8 ), lpad( diff ? "(" + diff + ")" : "(-)", 8 ), key );
+	}
+	process.exit();
+});
\ No newline at end of file