Instead of preparing for my up coming candidacy exam, I looked to to some interesting "social networking" sites online.
The first is del.icio.us, which allows to you store links or bookmarks to websites that you can access anywhere. You can also tag sites and view other people's links with similar tags. You can check out my del.icio.us links.
Another site, although a little obtrusive, is Last.fm. By installing a program on your computer, you can update an online profile with the music you have listened to. Your played music is then analyzed and you can listen to recommendations based upon the music you like and see other people's lists that are similar to yours.