I agree with what you have said about Firebug. I absolutely cannot live without it. The Inspect feature of Firebug is priceless especially when working with the DOM. It's easy to use and it is in the same window. I do not have to switch windows to look at the html source.
For now, I just use Chrome for my "24/7" tabs like feeds and online email. I never have to close them and it loads at "notepad-like" speed :)
I've actually been using Fluid (http://fluidapp.com) for all my 24/7 stuff -- gmail, basecamp, github, hacker news ;) It really already does what Chrome's detachable websites feature kind of does, only better (for now at least, I'll give it time :).
For now, I just use Chrome for my "24/7" tabs like feeds and online email. I never have to close them and it loads at "notepad-like" speed :)