KMAN,
Unreal is a great game, I play it on the PC. I'm not sure if they have multiplayer for PS2. I think they will for Unreal 2003. I play mostly PC online games. Not sure of the availablity of consoles. Although a friend of mine play a new game for X-box on X-box live, Mech Assault and it is awesome. I believe that game is X-box only.
I'm almost positive that unreal tournament or unreal 2003 is available for online play. Look into that one, you'll like it.