We already blogged about Firebug, a fantastic, must-have, and free Firefox extension for web developers. At Orbeon, we find Firebug invaluable to debug the Orbeon Forms platform but also XForms applications written with Orbeon Forms.
Well, version 1.0 of Firebug is just out, and Yahoo! has put up a video of a presentation by Firebug author Joe Hewitt showing off the less-known feature of Firebug. Even if you already use Firebug, you may learn a few useful tips from this presentation. We heartily recommend it.