Here are some websites where you can select tunes that are tailored to your routine with just the right number of beats per minute (BPM) to get you moving.  Research suggests that listening to music with a BPM of 120 and higher might get you to move faster.

how it works: It searches your iTunes library for songs to match BPM’s from 70 to 200

Price: $2.99 for the app (for the iPhone and iPod Touch) or pay what you’d like to download the desktop version

How it works: You choose 20-60 minute plus music mixes by workout type, then download them to your iPod or other handheld device or computer.

Price: Free

How it works: Runners will love this one.  Calculate your personal stride rate (from 140 to 185 BPM) and then download a 30 minute score of music designed to match it.  Just click “get music now”.

Price: $5 per mix

How it works: Pumped up music tracks and workouts from Lance Armstrong, Serena Williams, and more.  Check out playlists or search for “Nike Sport Music” on iTunes.

Price: $10.99 and up.