What could be better than killing zombies? How about killing zombies... for free? You'll recall our recent coverage of free online FPS Combat Arms. Over the holidays, a new map called "Cabin Fever" was released, featuring the survival style of gameplay that has become so popular. Almost half a million matches later, 278 million zombies have met their doom (for the second time, I suppose). If your wallet is light after all the holiday spending, you might want to check out Combat Arms for your zombie slaying fix.