I've used a the Mother's powerball for headlights with decent results, but over the last weekend I tried 3M's. I will never use another! My 4runner headlights look new now!
3M Headlight Kit
I used it with a standard 18V cordless drill, worked great. Note: make sure you double and triple tape the edges around the lights! At one point I slipped off the headlight and onto the tape. The sandpaper ate right through the tape and scuffed my paint. It was an easy fix, just used the supplied polishing pad and polished it back to a nice shine, but 2-3 layers would have prevented it.