When I'm buying something at a shop and I pay with cash I rarely have the right money so I usually get some loose change back. When this happens I look for a charity tin to drop the small coins into. I'd like to claim this is an act of generosity and altrusim but I can't. For one it's not very generous since it's only small change, and for another it's not very altrusitic since I do it mostly to reduce the hassle in my life. I go to great lengths to try to keep my life hassle free and I don't like lots of loose change in my pocket.
Of course, giving away my small loose change means I'm unlikely to ever have the correct change which creates a pleasant reinforcing feedback loop - broken only when there is no charity tin :-(
Doing this on my own doesn't make a lot of difference, but if everyone did it... Are you willing to give away your small change each time you shop? Would you sign up to a "campaign for small change"?