@David:
Have you checked out a recent nightly build for WebKit (
http://nightly.webkit.org/ )?
The "inspector" is curiously similar in all ways to the FireBug extension.
It’s layout is similar, the right click brings up a contextual menu with "Inspect Element", you can pop it in and out of the main window, there is a console and a network traffic analyzer.
The main difference is that FireBug is written in XUL and javascript (as almost all mozilla extensions are) and WebKit’s inspector is written in Cocoa, directly connected with safari (as a bundle ATM) which means that it is indescribably faster and feels much more "Cocoa" (obviously

).
The other thing I noticed about FireBug is that sites that use a lot of javascript take so frickin long to load when FireBug is running that I want to force quit. At this time there are still a few things that the fox can do that Safari can’t, but that gap is closing very quickly with each build of webkit (hell, most of the RTE’s work with the latest nightly!). Personally, It is rare for me to even open FireFox any more. My main browser has been WebKit since they included the inspector bundle. I also use
NightShift which downloads and installs the latest nightly build whenever I feel like updating.
-sD-
Dr. Scotty Delicious, DFPA.