This video shows the viewer how to boost, gain XP very easily, on ‚ÄòCall of Duty: Modern Warfare 2‚Äô. The first stage is to get a friend to join your game. Then search for the Team Tactical game mode until domination appears. Then back out and go to a private match. Change your clan tag to ‚Äòaaaa‚Äô and hover over Ground War until the game starts. The map usually used for this is Rust as it is so small. The game will behave like a private match but you will be gain XP for all kills. This glitch had not been patched at the time this video was published.
For more information and an instructional demonstration please see the video.