Zipcar, which rents cars by the hour to its members for short-term use, is expanding its on-airport locations, adding seven more for a total of over 50. The new ones include Orlando and Tampa.
For those who aren't familiar with Zipcar, it works like this. Cars are parked in parking lots on campuses, airports and city locations; make a reservation, and you're told where your car is waiting. You use your electronic membership card (there's a monthly fee) to unlock the car and drive away. No paperwork; reservations are made online or via a phone app.
When you're done, you return the car to the spot and walk away. Hourly rates run around $8-9, and daily rates are available. Gas and insurance are included.
A weakness for airport use is that, except for testing currently underway, no one-way rentals are accepted. That means you can't rent a car to drive to your final destination and leave it there...you have to keep it until it's time to return to the airport. Until one-way becomes more available, that may limit airport users. More detail at Zipcar.com