One things I recently tried in firebug, and which seemed unnecessary hard: I tried to get a list of all the event handlers that fired. Yes, you can go in the source view, and there on "trace events" or whatever it's called (why doesn't that work in the DOM view?), but when there's a page reload, tracing is off again.

And as soon as there's a handler for mouse movement, you see nothing else in the flood of onmouse* events.

(Maybe there's an elegant solution to this problem already, but I didn't find any).