In this week's paper, I spoke with Gregg Gillis, a.k.a. Girl Talk, and asked him for etiquette suggestions for this show. He had this to say:
Give yourself a little bit of space.
"It's not like going to a dance club, it's not like going to a concert.
At the same time, it's still dance and celebration music to me. You can
do that in a crowded room, you can do that shoulder to shoulder. But a
lot of time at shows, everyone's pushing forward, everyone's trying to
get onstage, everyone's trying to be involved so much -- and again, I
really respect that enthusiasm. But you should take a step back and
realize that it might be really fun to have an inch of breathing room,
so you can dance with someone and enjoy it. Sometimes the shows where
the crowd is actually spread out a little bit, it can be very conducive
for the show, and everyone can get a lot more insane -- rather than
being smooshed together for a half hour."
More tips at this link. Now, if you've never seen Girl Talk, I do suggest preparing yourself for uncoordinated dancers (regardless of whether they're under the influence of alcohol). This video doesn't really convey the insanity of the crowd -- if you can't stand to be in places where folks invade your personal space, I suggest not being near the front -- but it does underscore how unselfconsciously nerdy Gillis is, and how he manipulates and layers music together for maximum booty-shaking.
The following clip is a better representation of what to expect.