I am sailing on the Explorer 11-2-02 and have booked a room at the Best Western Marina Park. It is very close to the port of Miami and we have a room with a bay view so we can watch the ship sail in on Sat. a.m. This hotel has a web site and you can view the hotel. It is not a 5 star hotel but the location and $79.00 rate make it very appealing!
Priceline is your best bet. Hotels in Miami for pre cruise nights are routinely going for $30 for the Hyatt Regency. Last night I bid and got the Hyatt Regency, a 3* hotel in the Downtown Miami area for $30 staying on 9-27-02.
If you like the beach - We just stayed at the Holiday Inn South Beach for $45 through Priceline. It was very nice and we got to start working on our tan while relaxing on the beach the day before our cruise.