On the advice of some fellow cruisers I used the Ft Lauderdale water taxi prior to my cruise. For $5 you can ride all day and enjoy the sights of Ft lauderdale and see how the other half (the RICH ones!) live.
I picked it up just a short walk from the Embassy suites under the causeway and rode up to the A1A beach area, walked around and had lunch then rode back. Probably the best $5 I've spent in a long time. Highly recommended.
We stayed at the Mariott Marina after our cruise last Thanksgiving. Staying an extra night saved us $200 in airfare, which more than made up for the hotel and meals--plus we got to extend our vacation an extra day. And we second Doug's recommendation for the water taxi. It was a great way to see the mansions along the canals. One of our tablemates on the cruise had talked about their nephew having sold his house in Ft. Lauderdale for $12 million. After seeing some of these houses, it's easy to see that price.