Mashable.com, the "web 2.0" blog, frequently puts out roundup-style posts, where they'll list around 30 related sites or tools. Today, they have a couple interesting ones:

300+ Useful Firefox Plugins - Lots of blogging, social networking, and security tools for Mozilla's little browser that could. I'm going to try the "Remove Cookie for Site" add on.

30+ Browsers - Not browser plugins, but 30+ browsers. I think I had heard of 4 or 5 of them, and regularly use 3 of them. (Firefox for most browsing, IE when Firefox doesn't render correctly, and Flock to create picture-embedded blog posts).