Came across this handy little “app” today. MultiFirefox allows for multiple profiles to use different versions of the FireFox. So you can keep your working copy of FireFox 2 and all your beloved extensions, and test/keep an eye on FireFox 3 beta. So far, the “old-school” del.icio.us extension is the one I’m really anxious to see work in 3.
There’s already a beta of Firebug that works in FF3, which satisfies a few of my itches. I’d also like to see the web developer extension, but it seems the dev of that one won’t release a version until FF goes gold. Scribefire seems to work, though I still haven’t gotten in the habit of using it. Tiny URL extension is another one that I’ve come to rely on, which isn’t FF 3 compatible at this point.