Index: wp-admin/js/page.dev.js
===================================================================
--- wp-admin/js/page.dev.js	(revision 10513)
+++ wp-admin/js/page.dev.js	(working copy)
@@ -197,8 +197,8 @@
 		return false;
 	});
 
-	//  This code is meant to allow tabbing from Title to Post if tinyMCE is defined.
 	if ( typeof tinyMCE != 'undefined' ) {
+		//  This code is meant to allow tabbing from Title to Post if tinyMCE is defined.
 		$('#title')[$.browser.opera ? 'keypress' : 'keydown'](function (e) {
 			if (e.which == 9 && !e.shiftKey && !e.controlKey && !e.altKey) {
 				if ( ($("#post_ID").val() < 1) && ($("#title").val().length > 0) ) { autosave(); }
@@ -210,5 +210,16 @@
 				}
 			}
 		});
+		
+		// If the user presses Control-S/Command-S, they are likely trying to save the Post, not the browser web page.
+		// We can override the default key press behavior and autosave for them.
+		tinyMCE.activeEditor.onKeyDown.add(function(ed, e) {
+			if(e.which == 83 && e.metaKey) {
+				e.preventDefault();
+				autosave();
+				return false;
+			}
+		});
 	}
+	
 });
Index: wp-admin/js/post.dev.js
===================================================================
--- wp-admin/js/post.dev.js	(revision 10513)
+++ wp-admin/js/post.dev.js	(working copy)
@@ -494,8 +494,8 @@
 		return false;
 	});
 
-	//  This code is meant to allow tabbing from Title to Post if tinyMCE is defined.
 	if ( typeof tinyMCE != 'undefined' ) {
+		//  This code is meant to allow tabbing from Title to Post if tinyMCE is defined.
 		$('#title')[$.browser.opera ? 'keypress' : 'keydown'](function (e) {
 			if (e.which == 9 && !e.shiftKey && !e.controlKey && !e.altKey) {
 				if ( ($("#post_ID").val() < 1) && ($("#title").val().length > 0) ) { autosave(); }
@@ -507,5 +507,15 @@
 				}
 			}
 		});
+	
+		// If the user presses Control-S/Command-S, they are likely trying to save the Post, not the browser web page.
+		// We can override the default key press behavior and autosave for them.
+		tinyMCE.activeEditor.onKeyDown.add(function(ed, e) {
+			if(e.which == 83 && e.metaKey) {
+				e.preventDefault();
+				autosave();
+				return false;
+			}
+		});
 	}
 });