added key handler for control-s to notebook, seems to work pretty well

IPython/frontend/html/notebook/static/js/codecell.js

@@ -70,7 +70,7 b' var IPython = (function (IPython) {'
         if (this.read_only){
             return false;
         }
-
+        
         // note that we are comparing and setting the time to wait at each key press.
         // a better wqy might be to generate a new function on each time change and
         // assign it to CodeCell.prototype.request_tooltip_after_time
@@ -82,7 +82,8 b' var IPython = (function (IPython) {'
         if(event.type === 'keydown' ){
             that.remove_and_cancel_tooltip();
         }
-
+        
+         
         if (event.keyCode === 13 && (event.shiftKey || event.ctrlKey)) {
             // Always ignore shift-enter in CodeMirror as we handle it.
             return true;

IPython/frontend/html/notebook/static/js/notebook.js

@@ -62,7 +62,13 b' var IPython = (function (IPython) {'
         $(document).keydown(function (event) {
             // console.log(event);
             if (that.read_only) return true;
-            if (event.which === 27) {
+            
+            // Save (CTRL+S) or (AppleKey+S) 
+            //metaKey = applekey on mac
+            if ((event.ctrlKey || event.metaKey) && event.keyCode==83) { 
+                IPython.save_widget.save_notebook();
+                event.preventDefault();
+            } else if (event.which === 27) {
                 // Intercept escape at highest level to avoid closing 
                 // websocket connection with firefox
                 event.preventDefault();

IPython/frontend/html/notebook/static/js/textcell.js

@@ -67,7 +67,7 b' var IPython = (function (IPython) {'
         // handlers and is used to provide custom key handling. Its return
         // value is used to determine if CodeMirror should ignore the event:
         // true = ignore, false = don't ignore.
-
+        
         if (event.keyCode === 13 && (event.shiftKey || event.ctrlKey)) {
             // Always ignore shift-enter in CodeMirror as we handle it.
             return true;