Last Sunday Red Bull's Flugtag was held on the Willamette River (downtown area) and the turn out was huge. It looks like there wasn't any room to be filled... people everywhere.
In case you don't know, the Flugtag is where teams build "things" to push off into the water. (Clearly I don't know about Flugtags) I guess there is a goal to see which 'thing' gets the longest distance airborn, but truly, its just to jump into the river. My guess is that most of the people don't have a clue as to just how filthy the river gets. We're always hearing warnings to stay out of the river. I hope the folks don't get too sick.
If you want to look at some pictures go here: http://portlandoregondailyphoto.blogspot.com/2008/08/sunday-august-3-2008-red-bull-flugtag.html