The one and only Blue Morpho (Morpho sp). Seeing one of these in the wild during the Costa Rica trip never ceased to amaze me. The brilliant blue color is the result of light diffracting off of millions of tiny scales on the wings; incidentally, this structural coloration is why specimens of these butterflies don't fade with time.
Crescent butterfly (Nymphalidae: Phyciodes sp.) from Iowa.
Owl butterfly, possibly Eryphanis lycomedon, from Monteverde, Costa Rica.