As long as that charity isn't the owner of the grocery store's yacht club I like this idea. In practice, though, the types of charities usually offered are a) the business themselves like Goodwill, or b) controversial at best (say, a Komen-eqsue figure). If there was a way to make this choice with less friction I'd be much more willing to give up change entirely.

IIRC it was a local food bank.