Cool. Cuz, it's not like the zombies are going to be lugging around anything other than ordinary stuff like money (useless in zombie apocalypse), so the only way to get stuff is to find it. Thus, you HAVE to leave the safer areas, and you can't camp very easily, or, well maybe you could but you wouldn't be able to build.
Also, a hunger mod would be good, but without costs, just finding food. You could have onActivate - Player - AddFood - (#), and have it disappear. I don't know how to make it on random bricks so people don't just camp the food spawns, but... yadayada.
Should make people slower, too, when they're hungry.