Overload glitch (Halo 2)
From Halopedia, the Halo wiki
This is a glitch that can be only done via Xbox Live or system link.
First, go to an object that is not part of the environment, but part of the scenery (bridge on Zanzibar, floating platform on Midship). Then get seven plus people to stand on it and put as many people/vehicles on the object as well. Have the people then look down. The object will eventually overload and disappear.