Where is your username registered? Find out with Usernamecheck
Usernamecheck scans 60+ different networks, from 12seconds to Zooomr, and tells you if your name is taken. The sites on the list are some of the best, most useful places to have an account, so it might remind you of something you've been meaning to sign up for. Or, if you're an Internet addict like me, it might remind you of sites you signed up for and forgot about. Either way, it's worth a look.