Actually, I've been using Vibram Five fingers.
http://www.amazon.com/Vibram-FiveFin.../dp/B002IAW8XC
They're very expensive, but completely worth it. I got into running a few months back and was using sneakers, getting nasty shin splints and my back was killing me. Read an article online about humans being naturally tailored to running barefoot, and sneakers were actually causing the problems. Vibram's Five Fingers are the closest thing to running/walking barefoot, and I love them. Since running in them, I've cleared up my back and shin problems, straightened my posture, and used muscles in my foot that I never realized I had. Plus, I get tons of strangers stopping me to ask questions. Give it a shot if you want to increase your strength and agility.