First of all, here is the update page where you can download very small extensions of all varieties that make using Firefox easier, faster, and more fun.
My favorite addons:
Blue Frog anti-spam. This program uses your gmail account to automatically reduce and report spam. Great service, it doesn't get in the way, and it's free.
Adblock. This program goes beyond Firefox's built-in pop-up blocker and blocks any ads that are on the screen--banners, extra links, flash animated ads. . .everything. I also use dutchblock, which gathers data from thousands of individual computers to help block all ads.
Here's how effective that program is: when I go to ESPN.com, all I see is content. Literally. Not a single banner, pop-up ad, or anything.
I also have Forecastfox which gives me a 3 day weather forecast and access to a radar screen, and only takes up a small area on my status bar at the bottom.
NoScript is a great program that limits how much information websites can send to me through my browser. I've allowed my favorite sites (gmail, THN, etc.) to function normally but now I feel better whenever I visit I site I've never been to before--and places like ESPN.com are limited in how much they can harass me.
Finally, I also got FoxyTunes, which lets me control iTunes while I have a browser up. Enough said on that one. . .
Anyway, I started this thread to help inform people on THN of these interesting little programs, but I'm also interested to know what other pluggins people use. Are there any other particularly cool or helpful programs that anyone uses? I'd be very interested to at least check them out.
