Everyone that knows me is aware that I'm addicted to games like Guitar Hero and Rock Band. It's only natural that I would be drawn to the game Tap Tap Revenge for the iPhone. It's a relatively simple concept, much the same as either of the two rhythm games I mentioned. You've got orbs that come down your screen that correspond to music being played.

There are only four songs included with the game which are separated into four difficulties. Two of the tracks are used twice (in higher difficulties) effectively giving you six tracks to master. Sure, that's not a lot of music, but the game is free, which more than makes up for it. You can also currently download four additional tracks to the game. It's very possible that more will be added over time. I'd definitely recommend this if you're looking for something to pass the time with.