@Error014: Great idea!

Coded a simple Zombie crowd simulation 2 days ago (based on my pathfinding code from the official goodies pack). The Zombies still block each other in front of doors and the like but it's a somewhat dynamic pathfinding with obstacle avoidance and region+path based static pathfinding that works on huge maps:

Video: http://youtu.be/QPFZCBAlGUU

"Falls das Resultat nicht einfach nur dermassen gut aussieht, sollten Sie nochmal von vorn anfangen..." - Manual

Check out my new game: Pogostuck: Rage With Your Friends