The 3-park Tour is called "Backstage Magic" and can be arranged through WDW Guest Services.
I took the tour this past Spring and highly recommend it for all Disney Fans looking for something "extra" in addition to the park attractions.
It is a full day (8-9 hours) and goes through Epcot, MGM, and Magic Kingdom. There is a bus that takes you from Park to Park via "backstage routes" but there is a LOT of walking once you get to each park.
Be warned that the tour can spoil the Magic for some people, who may regret having been exposed to the backstage workings of the World they love. Most others, however, will find a fascinating mix of backstage workings, secrets, and trivia that will enhance their future visits to the parks.
I believe it runs around $150-$175 per person and lunch is included (ours was at Mama Melrose's at MGM). The tour route and things you see may differ slightly depending on your tour guide and which attractions are closed for rehab during your visit.
Some of the things I found most interesting include: seeing the American Experience show from behind the stage, watching the Body Wars ride from outside the vehicle, touring the warehouse where they store the Christmas decorations, seeing the launch site for the MK fireworks, and touring the parade flost storage areas. There was also plenty of time for questions because our tour was small (8 people)!
Again, if you have been to the parks numerous times already and would like to know more about what you've experienced, I HIGHLY recommend the tour!
HAVE FUN!
