So you love zombies but are little strapped on cash to be a part of Z-Day? Maybe Valve can make things a little easier by offering Left 4 Dead for a whopping 50 percent off ($24.99) on Steam. This deal is for this weekend only and who knows when we’ll see it for cheap again. Besides, the PC version is home to some pretty sweet mods and don’t forget the free Survival Pack due out in the spring. Go forth and spread the word!