When I first started playing UT2k4, I found the Rosebum's Invasion RPG server. That server is one of the absolute best servers that I have ever played on.
Here is the link to download the Invasion Mod for UT3.
If you are interested in a demonstration then the video link below should help!
I am eager to get my own computer as soon as I can afford to do so, so that I can play this and return to the Rosebum team. Seriously...I am ready to kick ass and chew bubble gum!
*Duke Nukem...gotta give my props!* When the hell is the new one coming out for the PC?