Stead has put a Left 4 Dead 2 server up, it should be attached to this group. Here's the IP:

83.142.50.2:28012

The survival server is online on my colo box but limited to anyone who's a member of this group basically. It can be found at:

davie.ath.cx:8080
82.71.217.24:8080

Whichever. The use of the odd port is that that's one of the only free ones I've got open and I can't be bothered getting a hole punched through the firewall!