In October 2005! DH & I loved it!!! The cost is $80 (incl. tax) on the Disney Website. When you call to book the tour...You just have to do it!!...Ask if there are any discounts, ie. DVC, AP, Disney Visa card, and take the best deal! It was worth every penny and DH and I have talked about doing it again. They told us that they are designing a new, "off-road" Segway tour in Epcot, but it doesn't exist yet.
By the way, one word of caution...Since we did this my DH (a 52 year old big kid) has been looking for a used one!!! It was that cool!!
Good Luck & Enjoy!!!