Your friend owes you five bucks. What do you do about it?

Suppose you go out for tacos, and your friend forgets his/her wallet, or similar. You offer to pick up the tab. It comes to about five bucks. You tell your friend it was about five bucks, and s/he says s/he’ll get it to you soon.

Your friend totally forgets about it. This is someone you see regularly and socialize with. How do you handle it?