These little guys were all over my driveway yesterday. I don't know what they found so attractive in the gravel there, but I had to go slow to let them fly up and away without running them over or having them hit the windshield too hard.
My internet search turned up no matching images, so their name is still a mystery.
* P.S. Further research indicates these are Red Admiral butterflies. This particular one stayed on my windowsill for most of the day, so it's a male defending a territory and waiting for a lovely female to come by. It kind of spoils the magic, but they feed on bird droppings, which is probably the big draw in the driveway. More about them here: Animal Diversity.
Click the logo to find more shadow shots: