From now on, we SHOULD start replying to these questions by PM, if anyone is courageous enough to do it. Granted, we are a community bent on fair play, but we should also answer questions pertaining to the dark side.
An aimbot is a client side (meaning user end...not server end) hack that automatically fixes your crosshair over your target's head. Not only that, but it jumps from target to target once the one before it is dead. For some reason, I seem to think this was developed by spawn camping Face h0s. But who am I to say.
Be forewarned. The server side mod CSHP, which is quickly spreading across the land of good-natured UT servers, blocks client side hacks, including most aimbots. It also reports your IP to a website (I believe...I've seen it). And if any of us see you with it and using it ruthlessly, we will NOT be pleased.
The members of PlanetUnreal Forums do not condone any acts of cheating.