im completely in the dark about multiplayer
 

i connected my g5 to my friends laptop... and were not able to play multiplayer... i know basic stuff about networking.... but not really on a mac... it appears that both of us have the same IP address... and i cant really set it up so that changes... im curious if that has to do with why its not working, or if UT takes care of that for you... i looked in the instruction manual, and it kinda explained how to do it, but what i did didnt really change the fact that the games werent registered on the other computer... basically i want a simple peer to peer ethernet network that can play UT 2004... if anybody knows how to accomplish this it would be greatly appreciated...

Just use a router.

If worst case, just use a crossover ethernet cable with fixed IPs on both machines in the same subnet and you'll be fine with a lan game.