I'm not sure what's really that freaky about it, but Valve is going to allow gamers to experience Left 4 Dead on Friday, May 1st until Saturday, May 2nd for free. The event will take place via their Steam service, and gamers are invited to preload now to maximize their four player co-op playtime.
After the 24 hours is up, the game will return to it's $39.99 price point. I predict many a dead zombie this Friday, perhaps a freakishly large number. Oh wait - I get it now.
Source: Store.steampowered.com