Man, I am so jealous.
If lightsabers don't work out, you can always go with a giant battle using cardboard-and-duct-tape-weaponry (Grosse Pointe South High School's senior class had
one such battle on their front lawn between classes this year).
Nerf guns are better done inside, where you can see all of the darts you drop

I wouldn't use them outside if you have to clean them up. While playing Humans vs. Zombies on an abandoned farm where - while it may be not-environmentally-friendly - you can get away with not picking up all of your darts, I don't know if the Georgia Dome/surrounding area would appreciate finding them everywhere
