If I'm just making a quick stop at a gas station or convenience store, I leave the helmet on. If I'm actually stopping long enough to eat a meal, then I'll take it off, but I don't do that very often. In any event, I made a pact with myself not to care what I look like after or during from wearing a helmet. Headbands, bandanas, and pony tail holders, however, can work wonders.

I'd add that I've ridden in some pretty rural places and you'd be suprised how little any one I've encountered has cared.