Now this is some real "viral" marketing.

To celebrate the upcoming launch of their latest mobile social game Zombie Swipeout, Zynga has today unleashed a horde of zombies on San Francisco and New York City. This is the one time we won't tell you to grab your loved ones (and your family if there's still room next to all the guns) and head for high ground if you see a zombie shambling toward you.

Instead of eating your brain, Zynga's zombies are handing out "bloodpops"—delicious-sounding hibiscus mint popsicles. We much prefer this type of blood drive to the kind with icky needles.

The zombies will shuffle through midtown manhattan and downtown SF today, so keep an eye on Zynga's Twitter for progress updates and see the maps above for specific routes if you want to become one of the horde a popsicle.

Zombie Swipeout is a companion game to Zombiesmash!. It's one (big) part Fruit Ninja, with a George Romero twist and Zynga's usual suite of social features. It also features unlockable upgrades and a weekly tournament with your friends. Check out a trailer here.

The game will be out globally in the next few weeks, but if you just can't wait to slash some zombies, head to the streets of NY or SF today. Note: please don't murder any of these zombies. They're only actors. Let us know if you encounter any in the comments or on Twitter.