The port is 28342, I don't no if there's going to be a game up tonight or not, whatsisname is the only person currently able to host, so it sort of hinges on his schedule.
Well, if you host a game, you should use 28342. But when joining, you can typically use "0" to indicate that you don't care what port you play on.
I have a game up on the tracker right now, hosting with the Mac version after (I think) fixing the bug that was causing Mac hosting to not work. Can someone try and join? Do note that, currently, in order to see my game, you SHOULD put "28342" in the client port field when trying to join my game. Mars said he could see it, but couldn't join. I'm using Hydrolysis Plant from descent2.de (use the side menu to go to the Level Spotlight section) -- you should get that mission before attempting to join my game. If you see a "?" preceding the level name for my game on the tracker, you haven't installed Hydrolysis Plant correctly.