As Sam pointed out, hell has frozen over. I've practically changed over to Firefox and impatiently waiting for version 3 to come out tomorrow. I am one of the many who pledged to download tomorrow.
Compared to IE7, it supports my CSS much better. Which can be a problem. I make a site look perfect in FF, but looks horrible when many others pull it up in IE. No need to rant, but that's the way of the world. When developing, you must make it cross-browser. But this is also where the FF plugin for IE come in. I can easily change between browers within an IE tab to test a page. Also works well for site that require IE (OWA).
Another plugin is Ad-Block. I feel a bit guilty taking away ad content from sites, but most of the time I only do it for sites with HORRIBLE advertising. Example: Facebook. Advertisement are based on your personal status in your profile. I am listed as single, so they throw up singles ads. Makes sense right? Why is it that the majority of the ads sporting gay men? And yes, I know I opened myself up for jokes. Facebook is making a judgement, but they only looked as far as me being single. They didn't go the rest of the way to see what sex I listed as "interested in". *click* ads gone.
The plugin management, and autoupdate for each plugin is fantastic. I don't have to go back to the addon page to seek an update, it pops up and notifies me. Hooray. To be fair, FF3 RC3 has been a memory behemoth. I use it heavily @ work, and most of the time I cannot leave it running over night. It will typically crash once a day. Perhaps tomorrow will show improvement. Is that decent enough of a reason, Sam.