Spartan Laser Glitch

You can perform the Laser Glitch when climbing your way up to the top of Control Room on the last level of Halo 3, Halo. As your climbing up to the top, you will see Sergeant Johnson on the far left mountain side, helping you with his Spartan Laser.

The trick is to shoot him until he falls off the mountain. Two minutes later, he will respawn near you. (Make sure you get him to fall off the mountain or will attempt to kill you, and usually succeeds). When he is down next to you, kill him again (well, down him) and take his Spartan Laser, it will have either 3 energy left or 100, kill him until you get 100. That will have an unlimited supply, make sure you get two and leave it behind, otherwise when you kill 343 guilty spark, you will lose it. This help kill the flood, also its pretty cool.