This 2-line web page will hang Firefox 3 with Firebug on a Mac:
<body onload="debugger"> <img src="">
(With Firebug scripting enabled)
This completely hangs the Firefox user-interface, so you can’t access your other tabs. The only thing to do is a Force-Quit. I reported the bug but unfortunately I just don’t have the time and energy to learn how to fix it myself. Hoping somebody out there might have some useful insights.
Haha, I’ll use it to bother my mac-lover brother.
There is a better alternative, you can use the Webinspector in Safari.
This is a german page.
http://www.guerilla-taktik.com/adminstration/apple/firebug-ahnliche-funktion-fur-mac-in-safari/