I've been using delicious for several months now to keep track of the websites that are really useful, fun, or that I want to come back to look at later. It's sooooo easy to use. I've seen magnolia, a similar bookmarking tool, and it is so beautiful that I almost forget about how it isn't very easy to use. Delicious is easy to use, but ugly. I guess you can't have everything.
I've added a badge to my blog.