Camera shake filter?

I see in most good COD video's the guys use alot of camera shake effects for the external cameras -- what effects are they from exactly , like which programs do you use?

I was watching some yesterday and it occurred to me that what makes the movies look so cool is just this one simple effect. If they used the same effect ingame using the F3 'fly by' or the F10 free mouse look mode with zooming in having the most exaggerated shaking then ( just like a real camera does ) then I would be one happy customer.