A good alternative to Miami International Airport for getting to South Florida. The two airports are basically interchangible because of a cheap commuter train linking the two. To get to the train from FLL, you must take a shuttle bus to the station, since the distance is too far to walk. The shuttle is free but takes a long time (20+ minutes). The fare FLL to MIA is only about $4.
FLL has free wifi. The areas beyond security close at night. This is not an airport where I would feel comfortable sleeping at night, but I did find a grassy area to sleep nearby (during darkness only).