The Harry Leu Gardens in Orlando
http://www.leugardens.org/
are absolutely fabulous - 50 acres of roses, magnolias, bamboo, and tons of really exotic plants, flowers and trees. We also took a kayak trip down the Weeki Wachee river. You rent the kayaks and just float downstream on this crystal clear river. You might see manatees, gators, or birds, especially if you go early in the morning. The kayak outfitter is located next to the Weeki Wachee Spring attraction on the corner of US 19 and Florida SR 50. The space center is also an interesting attraction. With the traffic, though, it takes 1 1/2 to 2 hours to get there. Have fun!