I bought a cheap leather credit card wallet from Walmart. I keep it in my pocket all the time. It doesnt go in my purse.

When I go to the gym, I leave the wallet at home, but take my credit card and drivers license and put them in my ipod's leather cover. (has a spot for sticking credit cards or cash in it) Then the ipod goes in my gym shorts pocket where I would keep my wallet if I were wearing regular clothes. I ALWAYS have my ipod touch with me, so if my credit card disappears out of my wallet, it's probably in my ipod case.