Much thanks to Tom Peterson of Fermilab for helping me to identify this beautiful little moth.
According to him, the caterpillars feed on grape vines and other vines (we have lots of those running wild at the back of our lot). Also: "The best way to tell a moth from a butterfly is that the butterfly usually has knobs at the end of its antennae, or at least thickened ends. Moth antennae are generally string-like or feathery. But like all such rules, there are some exceptions and in-between cases."
Beautiful macros! And a cute little feller. I seem to recall from school that a moth's antennae are "clubbed", while a butterfly's are more spearlike. This guy's seem more like a butterfly's to me...