I'm getting into walking in the mornings before work, and I've found a really enjoyable way of walking at a good pace is to listen to songs on my mp3 player that are the right beat/tempo.

I googled and found some free 'beats per minute' analysis software. It scans your mp3 collection and lists out the BPM of each song so you can easily pick out the ones that are the right beat and put them all on a playlist.

To start I picked a song I knew I liked walking to and scanned it to see what the BPM was. My test case song was Bust a Move by Young MC, which has a BPM of 118. So I've got all my favorite songs with a BPM of 118 or so on my mp3 player now and it's great!