In Forge mode, change into the Oracle and enter the "Buy Items" menu. Go over to "Scenery" and scroll down until you find "Container-Open". Place it on the map, then scroll down and buy a Gravity Lift in the "Scenery". Place the Gravity Lift on top of the Open Container, then go inside and jump. You will become stuck to the ceiling. To get down, throw a frag grenade directly below you. It will lower your shields, but it gets you down. This glitch can be useful during custom matches to kill people when they walk through. Note: Try using a shotgun or an energy sword.