Best option?
Probably the best idea for dealing with a collision that I've seen is to send a drill up there, mine blocks of the asteroid and shoot it out the rear of the drill.
Basically, use the asteroid itself as "reaction mass" (wrong word, I know) to cause a shift in the orbit, enough to turn a disaster into a near-miss.
Quite how the launching of this rock would be achieved, wasn't really addressed though. Still, it seemed a fairly pragmatic approach.
Biting the hand that feeds IT
