Things to do in a glider while under Zero G

To reach Zero G in a glider (To clear it up for some people, that's a light fiberglass airplane with no engine, not a hang glider, which is much less comfortable but way more fun) you first must dive to reach a decent airspeed, about 90 knots or so. Then you pull up, experiencing as many as three or four Gs. Then dive again. The extremely sudden change in acceleration renders you weightless. Experienced pilots can pull this off for several excruciatingly long seconds.

1. Shout WOOOOAH really loud.

Skill Level: 0/5

Style Level: 0.5/5

Most people can do this right from the start. Try controlling your screaming, don't make it too frantic, otherwise that half a style point is lost. More adventurous people can try singing, adding a whole new level to the experience. 'Black Dog' by Led Zeppelin works notoriously well. See if you can pull off a whole verse, given the time you've got.

2. Play with your stationery.

Skill Level: 2/5

Style Level: 0/5

Pull your log book and pencil out and let go. Kind of slightly fun at first. Sort of neat, just watching them there, floating like it most certainly wouldn't if you were on the ground.

3. Have a drink of water.

Skill Level: 4/5

Style Level: 5/5

Highly Recommended. Squirt a ball of water out into the air, and... It just hangs there. So unnatural to watch. Then purse your lips and drink it up. See how big a ball you can make, sort of like the world's most obtuse sculling contest.
Also, try not to wet yourself. Just suggesting.

Advanced pilots can pull this off during negative Gs, where the water forms a puddle on the roof of the canopy. Bring a straw. Invariably you get wet though, however certain people can execute a half barrel roll in this awkward situation, pouring the water conveniently out the ventilation window in the side of the canopy.

4. Pull some silly faces.

Skill Level: 0/5

Style Level: 2.5/5

Bring a mirror. The lack of gravity facilitates the pulling of faces that would normally be impossible on the ground. As soon as you hit Zero G, your cheeks will fly upwards, with nothing to hold them in place. Go wild.
Sometimes works even better in negative G.
Even funnier: Do this in a twin seater plane and pull faces at your co-pilot. They'll either join in or bog themselves.

5. Have a picnic.

Skill Level: 4/5

Style Level: 4/5

That's right. Pull out your sandwiches, chips etc and try to eat them in mid air. You've all seen the videos of NASA astronauts eating M&Ms in space, now try it out for yourself. This one is incredibly fun on repeat dives; what was previously a mess you would have to clean up, floats back up into mid air again for you to feast upon. Try humming 'Blue Danube' like that episode of The Simpsons.

Not Recommended:

Carbonated beverages. They explode at altitude. Long, messy story.

Anything erotic. Yes, I mean that.

Blacking out. They'll put you on the bus back home, that's if you do wake up in time...

Confetti.

Reading the newspaper. Again, long story.

Dentures.

Ride of the Valkyries at full blast. That's just plain old now.