Partway through my time in college, my chapter really wanted a sign, and found "shooting the arrow," which is just pointing your hands upwards diagonally. I'm about 95% certain it's supposed to go a certain direction, but I'm directionally challenged and never remember which. But, it's a pretty common thing to do, so you can find lots of celebrities "repping" Pi Phi.
For instance, here's Dean Winchester "shooting the arrow":
http://image.wikifoundry.com/image/1...2723/GW254H159
There's also some business about linking hands and forming wings, as well as "haloing" girls below you in a picture.