Here’s my iPod + running secret that works great for out and backs. I made a series of mixes, each with the aim of being varying lengths for my different work out goals. I.E. 30 min mix, 40, 45, 60, 90 and 120. You pick a center song to be your run mid point (so you know when to turn around- a watch is fine but I always found myself checking it every 2 minutes.) For the center song, I used the same one in every mix as a sort of pavlovian trick, specifically XX:XY by Blonde Redhead.

Next, alternate fast short songs (for sprints) with longer slower songs to help you with your pace.

This project takes a little knowledge about your song library and some tweaking, but doesn’t cost a thing, and always managed to get me excited to run.