My one item...
My laptop of course! Get on the net, let you guys know what's happening.... wait for rescue. You'd come right? .... guys? ... helloooo...
Well, I guess I could throw it at the nearest assailant. I'm not sure about the balistics of a MacBook, but I bet it would hurt.
To be perfectly honest, I don't know how safe a gun, any gun (within reason of course) could keep you. Large numbers of insane-o's with intent to do damage. Unless you have a good group of heavily armed lads for backup, I'm thinking staying away from the mob is your best bet.
But if I have to choose.... my coach gun. Two barrels of 12 gague still commands some respect.
Regards.
D