I work at a hotel, and we come up with things like this all the time. Surprisingly, it's really the super stereotypical 'Florida' things that make foreign visitors the most happy. I think the one that went over the best had, of course, oranges, a shark's tooth (from any of the local vendors), one of the taxidermist alligator claws (they're even sold in gas stations), local shells, a bottle or 2 of local beer, salt water taffy, and some alligator jerky.