While searching around google, I found theZombie Infection Simulator, which is interesting, but fairly limited. I am very interested in working with a Flash developer to make a web based zombie infection simulator.  Contact ZombieMenace if you think you can help.

UPDATE: We have found the best Zombie Infection Simulator here: http://www.class3outbreak.com/zombie-outbreak-simulator/. We are working to get permission to include it here on ZombieMenace.com.  Check back soon for more details.

Zombie Infection Simulator Links:

• The Original Zombie Infection Simulator - 2D Java based simulator with some user interaction.
• Matt Cordes' modified version
• Alan Gordon's 3D version
• Hardcorepawn's nuke-dropping game variant
• Mario Lopez's Incredible Zombie Machine
• Zombii - By Derek Ledoux zombie infection simulator prototype featuring zombies civilians and military members with weapons.