Reclaim 250 msecs on iPad and WP7.5 (Mango) by simply combining find().filter() calls and getting rid of fake pseudo selectors :eq(0) and :last.

Author: jblas

js/jquery.mobile.controlGroup.js

@@ -14,9 +14,9 @@ $.fn.controlgroup = function( options ) {
 						shadow: false,
 						excludeInvisible: true
 					}, options ),
-			groupheading = $el.find( ">legend" ),
+			groupheading = $el.children( "legend" ),
 			flCorners = o.direction == "horizontal" ? [ "ui-corner-left", "ui-corner-right" ] : [ "ui-corner-top", "ui-corner-bottom" ],
-			type = $el.find( "input:eq(0)" ).attr( "type" );
+			type = $el.find( "input" ).first().attr( "type" );
 
 		// Replace legend with more stylable replacement div
 		if ( groupheading.length ) {
@@ -33,7 +33,7 @@ $.fn.controlgroup = function( options ) {
 			els.removeClass( "ui-btn-corner-all ui-shadow" )
 				.eq( 0 ).addClass( flCorners[ 0 ] )
 				.end()
-				.filter( ":last" ).addClass( flCorners[ 1 ] ).addClass( "ui-controlgroup-last" );
+				.last().addClass( flCorners[ 1 ] ).addClass( "ui-controlgroup-last" );
 		}
 
 		flipClasses( $el.find( ".ui-btn" + ( o.excludeInvisible ? ":visible" : "" ) ) );

js/jquery.mobile.forms.checkboxradio.js

@@ -14,7 +14,7 @@ $.widget( "mobile.checkboxradio", $.mobile.widget, {
 			input = this.element,
 			// NOTE: Windows Phone could not find the label through a selector
 			// filter works though.
-			label = input.closest( "form,fieldset,:jqmData(role='page')" ).find( "label" ).filter( "[for='" + input[ 0 ].id + "']"),
+			label = input.closest( "form,fieldset,:jqmData(role='page')" ).find( "label[for='" + input[ 0 ].id + "']"),
 			inputtype = input.attr( "type" ),
 			checkedState = inputtype + "-on",
 			uncheckedState = inputtype + "-off",