The Great Lakes Kite Festival benefits the Children's Leukemia Foundation and is held every year in late May at the State Park in Grand Haven, Michigan. The weekend features giant kites, kite competitions (racing, fighting), kite seminars and demonstrations, testing, night flying and open flying.
Oldbrushes has a gallery of photos from the festival and you might also want to check out the Great Lakes Kite Festival on Absolute Michigan and this cool gallery of giant kites from 2005.
Editor's note: When I saw these pictures I said "Dang I wish I had known about this cool event". Then I checked "Off the Couch" on Absolute Michigan and realized that I had no excuse. Sorry, Mr. Stevens for not paying attention!