It doesn't matter what you wear/just as long as you are there.
Yesterday was the high point of the festival, with a parade stretching through much of the southern part of the city and lasting most of the afternoon and into the evening. I got there early and saw the first thirty or so floats go by, most of them followed by people dancing and drumming in various kinds of native costume. There were also a few political groups, including Greenpeace, some of whose members were dressed up as polar bears and penguins, with signs reading, "Got an iceberg?" The weather wasn't very cooperative, though - it started raining about an hour and a half into the parade - and, annoyed with the stupid-people behavior of some of the other spectators in my general vicinity, I left and headed home. (The stupidity included a women who had brought two dogs with her and was trying vainly to stop them from wriggling at the loud drumming, two women scolding the first woman for bringing her dogs, a guy behind me who kept jabbing me in the shoulder and asking me if there were more floats coming, and various drunken loutishness).
Later that evening, though, I went back and met a few friends at a different part of the parade. At this point, the displays of people in native costume had mostly been replaced by floats blaring dance music. Audience participation seemed to be the rule; behind every float, there was a group of people who just danced along with the parade. My friends and I found a float we liked and followed it to the end of the route, then went back and did the same thing with another float - one of the last ones, as it turned out. It's actually not all that easy to dance and maintain a forward motion at the same time, but we managed, with a lot of head-bopping and various waving of arms. Then, as we were heading back to the U-Bahn, we got sucked into an improptu dance party in front of a restaurant that had opened its porch up and was blaring music out into the street. The deejay kept announcing that this would have to be the last song, or else the restaurant would get into trouble, and the crowd would roar imploringly, and he'd relent. We finally managed to disentagle ourselves after about an hour and head home.
Even after the nine months I've spent here, the Germans continue to surprise me. Scenes like the ones last night make me wish I'd been in Berlin for one of the Love Parades, when the city apparently really lets its hair down.