AirTran will no longer be flying out of Harrisburg starting in August. Frontier flies out of HIA four days a week. I think Tuesday, Thursday, Friday and Sunday. The flight time leaving MCO to HIA on Frontier leaves around 9:00 am so figure on it being an early morning to get to the airport, drop off the rental and get through security. We have friends flying out of HIA in June with a layover in North Carolina both legs of the trip on I think USAir. They are paying over $700 for three tickets plus they have baggage fees on top of that. I think you might be able to get something cheaper with more flight times out of BWI.