I've got a butterfly book, too--it's called Butterflies through Binoculars
, the field guide for the east. It's got some nice pics in it.
If I'm IDing butterflies in the yard, I may have to search a bit for the name, or to tell if I'm looking at a checkerspot or a crescent. I'm sure the butterfly doesn't care what we call it, but it's very satisfying to me when I can identify it for sure.