I found $640: now what?

[Utah]

I think it is cool that you turned it in and you made the totally correct but difficult choice, although I would have wanted a better guarantee. Who is to say that if no one claims it that the tellers friend doesnt come in and "claim" it?

The fact that the money is important to you makes the decision all the better. If you keep making decisions like that in life you will go far because almost inevitably, good things happen to such people.