Firebug : go to canvas!

goCanvas.js

//
// Make firebug going to facebook's canvas
//
// From Firebug console, just execute the following command
// Or make a bookmarklet: <a href="javascript:with(_FirebugCommandLine){cd($$(".canvas_iframe_util")[0].contentWindow);}">cd(canvas)</a>
//
// see: http://stackoverflow.com/questions/2495313/firebug-and-jquery-selectors-in-an-iframe#answer-2512156
//

cd($$(".canvas_iframe_util")[0].contentWindow);