Hovering Arbiter glitch
From Halopedia, the Halo wiki
On the level Quarantine Zone, at the end, when you are on board the Gondola, look behind you. Far behind you is a pillar. Go there and jump up onto it. Climb up. When you reach the top, and stay there for a few seconds, a very strong force will throw you back down. When back on the ground, you will hover rather than walk, and a pulling force will stop you from go towards the front of the Gondola. This force is unbreakable. You also can't jump.