J.L.
Dinosaur World, just off I-4 by Plant City, would be PERFECT for an 8-year-old boy. It looks cheesy from the freeway, but kids love it. It's also a nice way to spend some time outdoors - the exhibits are all in a very natural, very Florida, wooded area. Some of them are a little gory (dinosaurs fighting), but every kid I've taken there loved it.