Come, join my server. We're still working some of the kinks out, so join up and play on it. The IP address is: 22.214.171.124. The easiest way to connect is to open the United Offensive Multiplayer, hit the tilda (~), at the console type in: connect 126.96.36.199. We'll see you there.
Mods: Magnapacks, BBK X-pipe with cats, BBK CAI, hood struts, KYB Shocks/Struts, Eibach Pro springs, SS Inserts, CDC Light bar, Chrome 17" Bullits with Nitto 555 and N2O with dual purge
The problem is that you've got to buy the original and then get the United Offensive expansion. UO runs about $20, now. I think the original is probably around the same amount, since it's pretty old now.