Manatee County is thinking about it. Pinellas just did it. And now Tampa is rethinking its approach to backyard chickens. On March 2nd the Tampa Bay Times asked: "Has the urban chicken's time finally come?" That news story pointed out that while Tampa (technically) allows urban chickens, there is a 200 foot setback requirement that means virtually all urban and suburban lots don't qualify. And the Tampa Tribune, via Tampa Bay Online, confirms that the City Council will discuss the issue March 15th.
Hillsborough County Citizens for Backyard Poultry have an online petition and will likely get involved, even though their main focus is the unincorporated county. They had 162 signatures on March 6th. Here's a link to their Facebook page.