You can find tPW servers in the in-game server browser; after the Epic shutdown, use the new OpenSpy Master Server:
http://beta.openspy.net/en/howto/ut2k-engine/ut2004 (http://beta.openspy.net/en/howto/ut2k-engine/ut2004)
Have the following pieces of the puzzle to quickly connect to these and generally most other UT2k4 servers. If you do not have them, install them!
- Mega Pack
- Epic Onslaught Bonus Map Pack
- CBP Map Packs
- UCMP Map Packs