background at the main menu

[Draconysius]

Actually it's a lot easier than that. You could just find the image you want to use, convert it to .bmp, rename it "UnrealTournamentLogo" and drop it in your UT/help directory.

[Sunburn]

Why having so much trouble??
Search about the OSX Background Changer for UT, and you can import even your own images to place as default background

http://osx.beyondunreal.com/changer/

and be happy

Thanks man!