All Tripwire Games 50% off until January 2

As part of Steam's Holiday sale all Tripwire Games are going to be 50% off until January 2nd 2011. So if you have been waiting for a chance to get your hands on The Ball, Killing Floor, or Red Orchestra: Ostfront 41-45 head on over to the Steam Store now:

The Ball Steam store page
Killing Floor Steam store page
Red Orchestra: Ostfront Steam store page