dress up like bill lumgerbg (sp?) and walk around asking people if they can come in on sunday and tell them they forgot to put a cover sheet on there tps report.
We did this when I was a kid (when the movie was new) we wore coveralls, and made all the Ghostbuster regalia out of cardboard and coloured them with markers... we covered backpacks with black garbage bags and tinfoil, then connected a vacuum hose as the proton gun, you can construct the part you hold in your hand from cardboard as well... it took us a couple of hours, but we looked awesome, and spent no money...
Go as Bob Barker and someone else as Rod Roddy from "The Price is Right", you could also have someone dress as a contestant by making a tag with their name on construction paper and making them dress as a tourist.
We were thinking about ghostbusters but then we realized we all suck at art and can hardly put stuff together with our hands. If we could pull it off, yeah it would be sweet.