Well, the first thing I would do is rent a car in Miami, drive to South Beach and spend a couple of days never really getting over the jetlag by going out until the small hours.
Spend a couple of nights at the 1 Hotel South Beach, and explore some of the famous shopping of Lincoln Road mall, dance the night away at some of the Cuban bars on 15th street, and watch the preening people run the length of the sandy beach in the daytime.
Once you’ve had your fill of this frenetic city, it’s time to jump in the car and head south to Key West.
Take a trip out onto the water to spot dolphins or the ‘sea cow’ (the manatee), and by night go to Third Street South for a great selection of restaurants, bars and some cool galleries.