We've never stayed down that far. Last winter, we visited West Palm Beach and stayed in John Prince Park which is only about 45 miutes away. From what I heard, many of the deep south campgrounds were wiped out from Katrina and the few that are left are very pricy.
When visiting, make sure to check out Shark Valley. We spotted hundreds of alligators right along the bike path. Homosassa Springs is a beautiful area also. Manatee use this area and the Crystal River and it's neighboring warm springs for their winter mating grounds.
Here is a big manatee winking at me while we were kayaking in 3 Sisters Springs in the Homosassa Springs area. You can get right in the water with them and one kept pushing my wifes boat around with it's nose!!
We stayed a few weeks here and lost count of the amount of Manatee we saw. Kayaking in these springs is one of my favorite memories. There are beautiful campgrounds in that area also. Rock Crusher Canyon campground is a full service site with heated pool and every ammenity imaginable. It's centrally located in the state, but still only a days drive down to the Everglades.
We also had the nieces and nephews who were staying at Disney (only an hour away) come over and spend a few nights with us, and they went crazy with all the manatee. They still ask about them everytime we talk with them.
Also check out Anna Marie Island which is on the West Coast and absolutly beautiful. Most of the RV Lots were pricey and full, so we just stayed in a wal-mart, but the island was something to remember with it's white sand beaches and fantastic sunsets. Hope this didnt confuse you more then your orignal question...LOL
Good Luck and make sure to let us others know what you found out