I have the first test version of the MEAWS rhythm game written in Flash. It was much easier than I expected; if this actually works, I'm going to be disgusted.
If you're reasonably computer-savvy and/or don't mind wasting a few minutes, try it: rhythm test.
You need a microphone. The object is to discover if this is actually a viable cross-platform tool. There is (virtually) no user interface, no game, and no fun. You'll probably need to try running it a few times before you get anything happening. To try it again, hit "refresh".