Tangerine! takes your iTunes and analyzes the beat counts of all your songs. Then you can make play lists for workouts but the beats per minute. It has some built in options for workout types, and you can tell it how many minutes you want.
If you don't like the ones it picks, you can also use the beat count listing to manually make your own, or modify the ones it generates. And then you can put them on your iPod, if you have one. Or just play them on your computer.
I use it for my walks, turning on the iTunes visualizer while the walk playlist plays, and it's really fun to walk to *MY* favorite music. I enjoy my video walks (and outside, real walks, when I can) but listening to my favorite tunes just makes it even more fun.
So ... hope that might be useful to someone else!
kim
