Changing the laws in places that currently prohibit backyard chickens often comes up. Backyard Poultry magazine has a good article on the practical politics of getting the votes to change the laws.
KT LaBadie researched local ordinances for a paper at the University of New Mexico. It's available on the Internet. She looked at 25 cities and found each one handled the issue in a slightly different way from the others. This attractive flock of mostly Faverolles lives in California.
This is a helpful resource for moving communities into serving their residents, both those who want to keep chickens and those who have their doubts.