No matter how big the internal memory of your mp3 player is, after a while the songs that you want to hear are always the last you hear of. Well Yamaha seems to have thought of a unique solution, the Bodibeat it is an MP3 player designed to make exercise a little bit more palatable by automatically playing music that matches the pace of your movement. You can load it with 512mb of music, and using an internal accelerometer, the BodiBeat will pick a song that has a tempo as close to your bouncing up and down speed as possible. When you change your pace, the BodiBeat will change the music. You can also set it to play music at your optimum running or walking speed, which it figures out with a pulse monitor that clips onto your ear. If you get really ambitious, the included software allows you to design entire music-based fitness routines. It has some other neat features like tracking distance, keeping exercise records, and learning what types of music you like. The 9hr battery life isn't bad, but the half gig of memory makes it almost useless, since the whole point of this thing is to have enough music at different tempos to take advantage of the adaptive hardware.

Unfortunately it won't play anything with any sort of DRM on it, including iTunes music. Concept: good. Execution: horrible.

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