I usually fly in a day earlier and stay at the Rodeway Inn. They have free parking while you are cruising and they also have a free shuttle to and from the ship.
Also they have a free breakfast as well.
Carnival Liberty New Year's Eve 2007
Liberty of the Seas 5/2008+11/2009
Allure 1/16/ 2011
Independence of the Seas 12/29/2013 Booked!