The PlayStation 3 version of Unreal Tournament 3 has been the talk of the town for being one of the first ever console games to feature modding. Though you'll need the PC version to make use of the editor for maps, models, and so forth, having access to player-created content is still a huge feature. We've been testing these functions out, but have learned that the PS3 version—which hit stores across North America today—cannot accept mods yet. Epic Games team member Josh Adams has explained the problem on the official forums:
However, the PS3 mod tools aren't quite ready yet. We are working through some final legal/release issues.
When it's ready, you will need to download the latest PC patch and another PS3 Mod Tools "patch" that adds the full PS3 mod support to the PC version.
You will have to cook ypur mods for the PS3 specifically. You will also need removable media (memory card, USB drive, etc) to transfer the mod from your PC to your PS3.
Our tests show that the Unreal Engine 3 Editor has no way of exporting content specifically for the PS3 yet. There is also no utility to package the various .ini, .ut3, and .u files necessary for other mods into a format that can be extracted and installed by the game's import content function. Though the instruction manual contains some basic instructions, even the printed reference page is currently unavailable. This may be a downer for some who were looking to get mods going right from the start.
Source: Ars Technica