We always saved ours and returned them when I was a kid in Michigan - they were about 10 cents each and were returned to the grocery store where you bought it. I also remember we once had a teacher in high school tell us he made $1000 picking up cans, and a smart-ass kid asked if he reported that on his taxes.

But this varies a lot state-to-state. In San Francisco, it seemed to be the poor with carts picking up cans. (And the recycling company wanted you to report people for digging through the bins.) I think the deposit was rather low there and had no idea where you can return them to.