I discovered this toolbar extension for Mozilla (called StumbleUpon) that provides a unique way to surf the web. When making your profile, you tell it what subjects you are interested in, and, via the “Stumble” tool on the toolbar, you can jump to pages relevant to that subject. Then, if you like the site, you click the “like it!” (or “not for me” if you hate it) button, and it can then learn what kinds of sites you like or don’t like, and can make more accurate suggestions for future “stumbles”.
It suggests the sites that it doees based on other users, who suggest sites via their “like it” buttons. You can post comments about the stumbled-upon sites as well, as well as read what other users had to say about it. You can join user groups, make friends with other users…you even have an rss feed on your site picks and comments. It’s quite neat, and I find myself spending way too much time looking for keen new sites. Here’s my stumbly profile.