Smarterer.

Smarterer is a free online testing site which is currently in beta. People who are internet and computer savvy will likely do well on these themed, timed test questions. Think you know iPhoto well? Show your worth to the online community by becoming master, expert, proficient, familiar, or beginner (the skill levels). There are tests on WordPress, Facebook, StumbleUpon, and useful topics, like science. Of course, there is a bit of competition; you can get bumped down a level if someone beats you on the score card. The site sends emails letting you know if you've been bumped or if more questions have been added to your tests. The latter gives you a chance to increase your score. You can sign in with Facebook, Twitter, or your email.

I tried out the site because I'm a BzzAgent and I like to be on top of things. However, maybe this wasn't the campaign for me. I don't have a competitive bone in my body and could generally care less about how well or not well people know their way around Twitter, etc. There are people out there that do like the competition and they do like to show off and prove their knowledge of computer applications. If you are one of those people, go for it. Not only can you prove yourself, but you can learn as you go along because they show the correct answers.

The site is http://smarterer.com/. Good luck!