Somehow I had never heard about incredibox, an interactive beatbox application that lets you drag-and-drop your own perfectly in tune, quantised grooves.
Initial thoughts of "Oh, this seems cute" quickly gave way to "Man, this is brilliant." The animations on the little beatbox dudes, the way their eyes follow your mouse pointer as you drop beats, effects and melodies onto them… and then you click the "1" in the corner of the screen and take it to the chorus, only to have your own beat come back to you.
This is something else. A post on the Incredibox Facebook Page says that they're working on an iPhone app, and I couldn't imagine a more fun way to noodle around on the bus. Until then, we'll always have the free web app. Give it a go, and see what you can come up with.
I like to play it sparse with melody and chorus and layer on the effects and bass, but that's just me.
Incredibox [Official Page]