Any Ultra Marathon Trail Runners or Ultra Mountain Bike Racers?

I'm a design student researching Ultramarathon runners and the gear they use... just want to know what works and what doesn't work / what needs improvement or redesign. I'm hoping to create a product better than what's on the market -- if successful, my creation could go into production for the 2012 Olympics. Any help or dialogue would be extremely helpful.

john@FormMeetsFunction.com