See Joe Hewitt’s Firebug Power User Demo
Ajaxian have a great article and video of Joe Hewitt deomnstrating the latest version of Firebug. Well worth the watch if you want to get the most out of Firebug and improve your debugging and development on the Firefox browser.
[UPDATE]: there seems to be an issue with the link above, and many people are reporting that the video doesn’t play or has bad sound. If you have the bandwidth you can download and view a better copy from the yahoo theatre. It’s in mp4 format and should play fine in Windows Media Player or Quicktime.
It ran for me in the browser using Quicktime.