NASA: Both Virginia's Langley Research Center and Ohio's Glenn Research
Center offer online tours for free
Atlanta Zoo: The Georgia zoo keeps a "Panda Cam" livestream on its website.
Houston Zoo: There are plenty of different animals you can check in on with this zoo's live cam, but we highly recommend watching the playful elephants.
San Diego Zoo: With what may be the most livecam options, this zoo lets you switch between koalas, polar bears, and tigersin one sitting.
Walt Disney World: Set aside some time, becausethere's plenty to see here. Virtual tours you can take include Magic Kingdom,Animal Kingdom, and Epcot, just to name a few.