To get to the tiny island of Key West, at the southernmost tip of Florida and the southernmost city in the continental United States, you have several options. There are several direct flights to the Key West International Airport from Atlanta, the Bahamas, and most major Florida cities. The runway at the airport is too small for other international flights, so most flights have a transfer at an airport in one of those cities. Fares can be rather high, however, and a lot of people opt to fly into a city in Florida and drive down.
The bottom line is that, while in Key West, you are better off not having a car. Chances are that you are staying in or close to the Historic Downtown district on the western part of the island. If this is the case for you, walking is the ideal means of transportation as all the great restaurants, bars, shops and activity locations are in this area.