Have you been to the Art Museum on the Lake? Pretty nifty place...
Going there tomorrow along with the Discovery Center. The only nonstop back to dc is 6pm so we have a whole day to wander.
Milwaukee has some great ethnic celebrations. Of course, there's Harley Davidson. 
There's a huge Harley event going on this weekend but I don't really get into the whole Harley culture (I ride a Triumph or a Moto Guzzi depending on the mood). It's nice to watch the big groups of bikes drive by, though.
