Can a bent rim be saved?
 

Recently I had to ride a mountain bike on the road after getting a flat tire (don't ask why). Anyway, I now have a bent rim. Is there any way to make this thing right or do i need to just buy a new one?

Truing the wheel will most likely fix it. If the rim itself is bent, door-frames are your friends.

Bent how? Where? How much? Mountain bike wheel or road wheel?

Bent rims tend to be near impossible to true. Spoke tension adjustments make gradual averaging curves of the rim, and a sharp bend tends to always stay right there on top of the adjustments.
I'd ditch it.