Harmonix has released portable rhythm action title Phase: The Music is your Game onto iTunes.
It will cost you GBP 3.99 to download, and lets you use your songs as the in-game playlist to click along to.
The idea is to match the position of discs flowing towards you on a road by pressing the middle, left and right areas on your iPod wheel, and sliding your your finger or thumb around to match-up with flowing sweeps of dots.
Like Guitar Hero, the more you can hit the higher your score will be, with various multipliers rewarding you for clean passages. I say.
Sound like fun, though.