Is it me or are you sick of working out to the same old songs? I found a great way to freshen up my tunes without spending a dime. My running partner and I swapped iPods. If you don't feel comfortable letting your precious iPod out of your sight, then have you and your friend burn CDs of your favorite running mixes. Swap those and upload them to your iPod. It's an inexpensive way to make your workouts instantly more exciting.
Another added benefit: You will get to know your running buddy a little bit better through music.