American Airlines is now offering daily non-stop flights from Savannah to Miami (and vice versa)! They seem to run a bit over $200 and are about 2.5 hours.

Before this direct flight (just opened Dec 14th 2007), you had at least one connection, or had to drive to Jacksonville (a little less than 2 hr drive from Savannah), so it basically took less time to drive (about 8 hrs) from Savannah than to fly in the past (because of the connection and having to get to the airport 2 hrs before flight, etc).