Identification, please?

[Mark Mathu]

Hi, I'm hoping someone can give me a hand and identify the following:
http://www.geocities.com/SouthBeach/Boardwalk/4701/butterfly.jpg
(65024 bytes)

I took the photo when visiting Washington state's Whidbey Island, about 60 miles
north of Seattle.

Sorry, I have no identification books on moths & butterflies here, and I'm
hoping someone can make a quick identification.  I want to send the picture to
my seven-year-old nephew (who wanted me to take the picture), and I thought he
might enjoy it if I identified what was in the picture.  [I assume it's got to
be pretty common, since my nephew spotted it on the grass in mid-day.]

Thanks,
Mark Mathu / Milwaukee WI