What is U-ball?
When you're driving in the same direction for a while, and you realize you've forgotten something and have to go all the way back, you must "throw a u-ball". U-ball is just another word for u-turn but with u-balls you cover a much greater distance.
J: Paul, did you remember the money?
Paul: Aw shit. I forgot. Now I have to throw a huge u-ball. Fuck!