Not one to get by on looks alone, the BODiBEAT by Yamaha chooses the right songs to match the pace of your workout. While you're running or walking, BODiBEAT tracks the metrics of your workout including distance, time, pace and heart rate (using the small heart-rate monitor that clips to your ear).

There are four operating modes: free, fitness, training and music. In free mode, it matches the music to the exercise pace, selecting songs that mirror your tempo. The fitness mode includes settings for walking and jogging, each of which works in conjunction with the heart-rate monitor to select the most appropriate music for aerobic exercise at your fitness level. The training mode tells you when to speed up and slow down for ideal results. In the music mode, BODiBEAT functions as a standard MP3 player.

BODiBEAT lets you specify times, distances or calorie targets to help structure your sessions. When you reach the target, the music automatically stops and the workout is over. BODiBEAT has a paltry 512MB of flash memory, so plan on changing your music often. BODiBEAT will be available later this fall for $300. — Ken Sander