For anyone with a Mac and can't right click,
Drag to Tab is a life-saver. Command-clicking blows.
Unfortunately, however, it's hard to go back to Firefox after using the ridiculously fast and ultra compatible
Webkit browser. I do miss some of the extensions, although thankfully the most important (Adblock) does have a safari version. The only catch, however, is NO DRAG TO TAB. Alas, life always has a way of making me angry.
As far as other favorite addons, the only other ones not mentioned here that I love are "How'd I Get Here" and "Scrollbar Anywhere." The reason i dont link these is because there are no FF3 versions of these out. So basically, I have more fury. Those were awesome.
Also, sort of off topic, but the
multiclutch app is a MUST HAVE for MBP and MBA owners. It lets you set multitouch gestures to key commands. I can now go back, forward, switch tabs, open tabs, close tabs, and go to my home screen all on the track pad