Added inline SVG feature detection and use it for webkit fallbacks.

mobile.css

@@ -284,6 +284,10 @@ header #home {
     padding: 14px 0;
     line-height: 14px;
 }
+.no-inlinesvg header #home {
+    background: transparent url(../global/mobile/homeicon.png) no-repeat 0 12px;
+    padding-left: 22px;
+}
 .mini-header .site-title a {
     font-size: 22px;
     line-height: 22px;
@@ -420,6 +424,7 @@ a.listview:before {
 }
 
 #search button[type=submit] {
+    display: block;
     margin: 0;
     height: 45px;
     width: 56px;
@@ -434,6 +439,10 @@ a.listview:before {
     vertical-align: middle;
 }
 
+.no-inlinesvg #search button[type=submit] {
+    background: transparent url(../global/mobile/searchbtn.png) no-repeat left top;
+}
+
 /************************************/
 /*              FOOTER              */
 /************************************/

mobilefeatures.js

@@ -0,0 +1,35 @@
+/*
+ * In general we assume modern on the mobile site. We don't need full
+ * modernizr, but there are features we want to test for.
+ */
+
+// Tests below are copied from Modernizr
+/*!
+ * Modernizr v1.7
+ * http://www.modernizr.com
+ *
+ * Developed by: 
+ * - Faruk Ates  http://farukat.es/
+ * - Paul Irish  http://paulirish.com/
+ *
+ * Copyright (c) 2009-2011
+ * Dual-licensed under the BSD or MIT licenses.
+ * http://www.modernizr.com/license/
+ */
+
+
+(function() {
+
+"use strict";
+
+// Inline SVG is not in iPhone or Android webkit _yet_, so we need to fallback.
+function inlineSVG() {
+  var div = document.createElement('div');
+  div.innerHTML = '<svg/>';
+  return (div.firstChild && div.firstChild.namespaceURI) == 'http://www.w3.org/2000/svg';
+}
+if(!inlineSVG()) {
+    document.documentElement.className += ' ' + 'no-inlinesvg'; 
+}
+
+}());