My wife got me these “Moon Shoes” from one of those toy store going out of business sales. According to the literature, they absorb about 60% of the impact while running. I’m not ready to try a 2 mile clip yet, but I think after some modifications these might be fun to go grocery shopping at the mega-mart. Here are a couple pictures. There are some pro-level versions of biped enhancers I’ve seen at conferences with a trained team that does flips and stuff- seems kinda interesting.