This is more of an ipod hack, but it did also work on an iPhone...

During my final year of school at Northeastern University, we were expected to design and prototype a product from start to finish.

I documented my project at http://ipulse.shred444.com. Comments are welcome!

I figured you guys might enjoy this...

mmmm.... nike + ipod sport package????

not at all similar.

Nike measures your footsteps with an accelerometer to plot speed and distance.

This beat matches heart rate with song tempo to select a song based on your current exercise.