I have started the thread over at the EPIC forums related to this same topic.
The thread can be found here:
In UT99 there were two applications made by people in the community that did things we needed. ASC controller and UTDC.
UTDC was a small app that each client has to download in order to play on the servers that ran it. Then while you were on that server, the admin could log on, click a button and EVERY player would have a screen shot taken and that screen shot was uploaded to the server. At the end of the match the admin could download any screenshot from any player and see if they were using a cheat of some sort (such as radar or looking through solid walls, etc).
Also UTDC also checked each clients (or players) running scripts in the active memory. Basically when you connected to a serever, UTDC activated and compared the active scripts in the UT.exe file (the game scripts currently running) to the stock game scripts that should be running.
UTDC would then determine if the player had any additional scripts or hooks running that game them aimbot, or invulnerability or something a modified .exe file could provide them.
Is there anyone out there that could create something similar for UT3?