Here are some Xbox Live glitches for some of the maps.
*Get on the water.
This requires 2 people. First, go to the bench next to either one of the stairs that lead to the upper deck. Then face the bench and keep crouching up and down while moving forward until you get up on the bench. Now go to the end of the benches (while still on them) and have someone else go near the middle of the benches. And face the water. Have him crouch and then start running toward him. Once you hit him, keep moving until you get on top of him. Then, carefully move across him and go overboard. You should now be in the water!
*Get in the Garage
Go to the far benches in the upper deck and repeat the steps you did to get in the water. This time though, you walk the opposite way from the other person.
*Get out of the map boundries!
This glitch requires any kind of connection with a standby button.
First, go to the hangar and get halfway up the ladder near the windows. Then go to your router or modem or whatever you have and do the standby button for about 7 seconds and/or keep holding it. Then start going up the ladder...on...and on...until you start climbing up an invisible ladder to the roof! Now you are able to go across the building and out of the boundries. This tatic also makes you invinsible the moment you start walking up the invisible ladder and stays that way until you step into the boundries again. This is great for cheating your ELO or shortcuts for Retrival and the other thing with transmitters.
I think there is more glitches, but these are what I know.