I'm surprised no one's posted about this one yet. The (5th?) annual Northwest Supercub Fly-in is this weekend, June 27 & 28, 2009. It will be held at Cascade Airpark, about 2 miles east of Harvey Field near Snohomish WA. There will be STOL contests, flour bombing, some gravel-bar flyouts for the hardcore, and lots & lots of really nice Cubs. You can compete, help out, or just watch- whatever blows your skirt up.
I was little apprehensive the first time about flying in with my 170, esp as I'd been given a hard time before at 180 get-togethers due to my choice of airplanes. But this will be my 4th year attending, and other than a little good-natured kidding from friends, no one's ever said a derogatory word. So even if you don't have a Cub, you'll feel welcome. Food's available onsite, and camping under the wing is permitted.

Eric

Couple things I forgot to mention:
1) CTAF is 122.9, but be aware that there may be some NORAD airplanes attending.
2) STOL demonstrations, etc start off at 10am saturday morning, so be vigilant with regards to airplanes in the pattern and airplanes & people on the runway-- pilots will be concentrating on what they're doing, so may not be making a lot of position reports. Airplanes and people will frequently be stopped on the runway in order to measure takeoff & landing spots.
3) One of Harvey Field's skydiving drop zones is just a little ways northwest of Cascade, so be vigilant for them. The jump planes transmit advisories on Harvey's freq 123.00 . It might be best to approach Cascade from the east- fly to Firstair Field (W16) in Monroe and then follow the railroad tracks west about 3 miles until you see Cascade on the north side of the tracks.

Eric