There are no in-game mod tools that run on the PS3, but these tools allow users to create and release custom content for the Playstation 3. Make sure you have some type of removable media that you can connect to your PC. The PS3 can accept USB drives (including iPods), USB thumb drives, SD cards, Memory Sticks, and Compact Flash devices. Details can be found here.

Unreal Tournament 3 PS3 Mod Tools (2.25MB)