It is seldom that I like to just link to somebody without adding some content of my own - even so, since I fell in love with the current Firefox 3 due to its performance and all-round experience, I was more than happy to find a workaround to install extensions that have not yet been ported to version 3. Check it out here.
Now I can use Firefox 3 AND use my favorite extensions, e.g. easy gestures and firebug. There's the equivalent of a grinding sound at times when the options dialog of an extension comes up, but all in all it seems to work.