Are there any unknown/underrated web sites or services you think everyone should get familiar with?

www.gorankem.com The creator came to my new media class to explain it. At first, I didn't understand its use, but once you take a look you'll realize there are no other tools quite like it. Basically, it's a music recommendation system that rates an artists catalog based on people's votes. However, people who vote get to choose whether they're a pretty big fan or not so much, which can help you decide if you want to listen to them. Let's say you've never listened to Radiohead before, and their discography is so intimidating you don't know where to start. If you go by a most sold/most popular list like iTunes, you'll be told to start with Creep. However, when actual fans rank the songs, the number one choice is Paranoid Android. When I've looked at the artist pages of my favorite bands, the lists are far more closely aligned with my opinions of the best songs. More non-singles make it into the top. And it's fun to make lists and look at your friends' lists!