In thinking more about what you said, Dave, I guess it would probably be best to just stay at a hotel near the airport and take the shuttle the next morning. They'll be a group of 8 or 10 (some have still not decided) of us coming in on a few different flights and joining up at a hotel near the airport sounds a lot simpler.
Hi yagerbomb, welcome to Cruise-Chat. There have been some good reviews for the Holiday Inn-Bayside. If you're talking about south beach, we stayed at The Palms. It was a retro hotel, very nice, pretty expensive. There are tons of hotels in Miami, but the prices can vary widely. If you search for South Beach or Biscayne Bay or Bayside area hotels, you'll be close to the port. Last year, I believe Cruise Fanatic stayed at a Red Roof Inn near the airport. The cab fare was $24 to the port. Hope this helps a little. Best wishes!
We usually stay at the Holiday Inn Port of Miami. It is a $24 taxi ride from the airport and to get to the port in the am it costs $8 by taxi. It is just across a bridge... If you ask you can get a room directly overlooking the port so you can see your ship arrive. The hotel is directly opposite the Bayside Marketplace, which has lots of shops, restaurants, bars, all set around a Marina. You can eat shop and people watch. They usually have live music in the evening. It is a good place to stay pre-cruise.
I agree Wakewatcher. We stayed there too and enjoyed our stay. There is a lot to do across the street at Bayside. We spent a few days there and even went on a high speed tour boat. It was a blast! Our room faced the port. It is about a 5 minute cab ride to the ship.