I've been doing the warrior dash for a few years and love it, but I haven't seen any Zombie runs locally. If you have any info please send it my way, they look like a lot of fun.
http://escapefromrun.com/
Its so much fun. Much better than other 5k's for fitness because you get frequent bursts of sprints to avoid "zombies". The natl guard choppers and rigged explosions are all pretty fun too.