There is a website called roadid.com that sells id tags for cyclist, joggers and such. They have a dog tag that you wear or wrist and ankle as well as one that clips to your shoe. The neat thing about them is you can get a graphic like mountain biker or road bike on one side and your personal info on the other along with medical info or whether your a organ donor and blood type if you know it.

I just ordered one and there only like $24.99. Could save your life if your by yourself especially if you have medical problems which I do.