Here are a couple of controls for MW2 that weren't included in the instruction 
booklet:

ZOOM *OUT*: You zoomed in and now you have no peripheral vision. tap the 
"zoom" button _twice_. The folks at Activision only told you how to zoom 
in/magnify. this enables you to zoom out and restore the default cockpit view.

GLANCE: tap the "turn torso (left or right)" button twice. this enables you to 
look to your left or right without turning the torso away from your soon to be 
destroyed target

GROUP FIRE: hold the "fire" and "weapon select" buttons down together. All 
your available weapons will fire nearly simultaneously. This option was ever 
so popular on the PC version for granting your target a quick, but definitely 
not painless death. Just keep an eye on the temperature gauge though, there's 
no override function that prevents you from shutting down from overheating 
(that I know of.) 
Please note that this is not a "true" group fire as the weapon select button 
rapidly cycles weapons by default when held down. However, this still is 
better than waiting for your rocket launcer to cool down.

TARGET CLOSEST ENEMY: Double tap the "enemy select" button to highlight the 
closest target. By default, tapping once will highlight the target closest 
to the center of the screen. If there are no targets on screen the computer 
will then target the closeest enemy.

- Alvin