Walking in a ditch? Any reason why? I found a $50 dollar bill on the floor of a bar once. If I had any idea who had lost it I "might" have given it back. So, I just bought shots for people instead. Other than that I've never really been that lucky. I vaguely remember finding something small on the ground when I was a kid. Oh and I once found about $150 in a cd case in my bedroom after putting there a year or two before and forgetting, does that count ? =p
Then you might as well not touch ANY money!!! You have no idea where money might of been that comes out of da cash register. And for da really paranoid....you can always wash your hands!!!! *hint*