Hey you. Yes you at the back. This is a news item for you, as I think you are the only Co-Optimus member who has yet to pick up the fantastic Left 4 Dead 2. Now is your chance, because from today until 10am PDT on the 29th October you can download and play the game on Steam for free. There is also an additional achievement available for veteran players of the game.
Entitled "Good Guy Nick", the Steam achievement is won by helping a free weekend player survive a campaign. This means that you only have 4 days in which to snag this elusive prize. It may be tricky to get as there is no indication which players are new and which are not. Valve suggests that it is time to dust off those microphones and get chatting to see who is who.
You can download the game from the bottom of this page.