Taxi would probably be too expensive unless there are a bunch of riders. Last time we were at Orlando transportation was on a Greyhound type bus operated by Mears or Meers (don't remember) Transportation. They seemed to have a lock on transportation to the port. We were allowed to pay prior to boarding and did not have a Carnival transportation voucher. I think this is the same people Carnival use. Cost was $35 each. Do not know if it is cheaper to buy in advance.
52 Carnival: Mardi Gras, Ecstasy X2, Fascination X6, Celebration, Elation X5, Glory X5, Fantasy X4, Valor, Holiday X3, Imagination, Liberty, Spirit X2, Freedom, Destiny X2, Splendor X2, Dream X2, Conquest, Legend X3, Victory, Sensation, Paradise, Inspiration, Magic X2, Triumph, Miracle, Breeze
6 Norwegian: Sky, Jewel, Dawn, Epic, Pearl, Breakaway
7 Windjammer: S/V Legacy X3, S/V Polynesia, S/V Caledonia, S/V Diamant, S/V Sagitta