MW2 (2009) Secret Cheat Code
The Code: While holding RT and LT, press Dpad-Up, Dpad-Up, Dpad-Down, Dpad-Down, X, X, Y, Y
All the code does is temporarily unlock all locked missions
1: Works on Xbox, not sure about other platforms
2: If it isn't working you may just be putting in the code too slow
3: The code does NOT work for two player online spec ops
4: Your progress in the locked missions will not be saved
5: To get rid of the code just dashboard / reset your game