If you haven’t noticed the little orange badge in the bottom right corner of my blog (and from the stats, most of you have) I’m a fan of Firefox over IE. There are multiple reasons, but I’m through trying to persuade you to switch, I’d rather tell you about some of the great things I use at firefox.
I recently had to start my computer back up from scratch, which has meant restarting my firefox installation. Before I had added so many extensions that they were conflicting with one another and freezing up firefox at least once a day. I couldn’t bear to part with them though so I left it in conflict and just got used to restarting.
But, now I’m starting from scratch and I’ve decided to move quite slowly and only install my absolute favorite extensions, one at a time. So for those who have just entered the firefox extension world here are my current Must-Haves:

1. TabMixPlus– This is my first install because of a couple of the great features:
   -undo (restores tabs you closed right back to their original position with their history intacted)
   -Session Manager (restores all your tabs from the last time you closed Firefox, let’s me pick up right where I left off)
2. Google Toolbar– They greatest feature currently is that you can pick and choose which buttons to add to where on your toolbars:
   -Autofill (saves hours of time filling out forms)
   -Spellcheck (keeps me from looking like an idiot)
3. Greasemonkey– I wish I could explain how cool this is, but the list is endless. If you ever thought a site would be cooler if… there is probably a script for it.

And these two are more specific to your situation and interest:
1. FireFTP: for those who do webdesign easy upload
2. Screengrab: if you like to take full length screen shots of webpages