I'm not sure if this is considered cheesy or not, but this is how my school does it. All of the Rho Chi's wear an easy to pull off shirt over their letters. All of the NMs stand in a huge circle, and starting alphabetically we all sing the "Let me see you get down!" song. For expample for Kappa Alpha Theta it would go "Hey Thetas?" and the new members who just received their bids were reply if they were Theta "Hey what?" and so on. I'm sure everyone knows that song. During the part where everyone is "supposed to get down" the Rho Chis of that particular sorority runs into the circle of NMs and take of their shirts revealing their letters. I liked this idea because it shows all NMs where each Rho Chi belongs easily plus it allows the NM some pride by yelling for her new house.
