We had originally booked this cruise with intentions of going spending the weekend prior in New Orleans. When the cruise was switched to Galveston, Delta changed our flights, but we decided to just fly into Galveston the morning of the cruise. I have been on 8 cruises and have done this several times, but this time--it was a near disaster. Our connecting flight got cancelled, and all of the other flights to Hobby airport were overbooked. We were finally lucky enough to get a flight into Houston International, but our luggage went to Hobby. Fortunately we had time to take a cab to Hobby and pick up our luggage, and we made it to the ship in time. One advantage of being late was that we avoided the embarkation chaos, and practically walked right onto the ship.
Cab fare is very expensive from Houston. I would recommend the Galveston Limousine service which is $50 round trip/pp from Hobby airport, or if there are 3 or more people in your car it would be worth getting one from either Hertz or Enterprise and turning it in at their booth in the cruise terminal. They both charge a one way drop off fee, but it would come out cheaper for large parties.
We found out upon arrival that our itinerary had been changed secondary to Hurricane Wilma. Jamaica and Grand Cayman were cancelled, Cozumel was moved to Wednesday, and instead we we visited Costa Maya, and Progresso on Tuesday and Thursday respectively. I had a Dune Buggy excursion through a company called LTD tours set up in Cozumel, but they were able to change our tour from Friday to Wednesday.