We stayed in Miami a few days before our cruise. I found it mostly boring. We did go to South Beach for one of the days - hit the shops and then stayed on the beach. Lot of huge-tittied, topless women if that's your thing. I'm pretty sure that's an unofficial not really legal thing. We sat next to a woman who had the nicest rack I've ever seen in person, but I digress.
We hit the dumb shopping center in Biscayne Bay, did one of those boat tours to see all the cool houses, walked the streets. Be careful where you walk, there were a lot of homeless people and a lot of drug addicts. No joke about this next part - we're sitting on the beach and this homeless dude comes up to me asking for money. He takes off his hat and he has a festering wound from his forehead to the back of his neck. Right around that area was skid row and felt dangerous walking through. People passed out on sidewalks, fancy cars with body guards, etc. If you go the other direction it's just a regular city that doesn't look much different from boston (without the retarded street layout).