Buses and coaches, Orlando
By air to Orlando International Airport.
Most hotels have free shuttle services to major area attractions. I would recommend the 'I RIDE' trolley which travels from Sea World in the south to Belz Factory Outlet World in the north with convenient stops along the way, and it costs only 75c for a single fare ($2 one day pass). As a single traveller, I found the trolley useful to get around Orlando.
Disney Transportation is the best. No matter where you are on Disney property, you can get wherever on Disney that you want to go! We had a water taxi right outside our hotel that went to Epcot and Disney-MGM Studios, and there was a bus stop out front of the hotel. The buses were clearly marked and we took them to the Magic Kingdom and Downtown Disney (they did go to all the parks).
These colorful buses are free shuttle from WDW Village hotels to all theme parks at 1/2 hour interval. This is most convenient as one don't need to look for parking space & walk a long way from the entrance.
Mears transportation has shuttle service from the airport to all hotels. They can also take you from most hotels to different attractions. The price from the airport to area hotels is $24 one way, which is expensive, but generally cheaper than a cab. There's usually a wait, and since its a shuttle, you may have to make a few stops, so budget your time accordingly.
I flew into Orlando and stayed on-site at the the All-Sports Disney Hotel. We had to get a shuttle to the hotel - which took awhile even though we had reservations, but it was only a half an hour wait.
I used the Disney shuttle buses to go everywhere in Disney World - it comes with the room. We also caught a shuttle to Universal. I recommend using buses because it's cheaper.
The omnibus is fashioned after an old-timey double-decker bus with a spiral staircase in the back. It is one of several ways to get from the gate at Main Street USA to Cinderella's castle.
Orlando is provided by a bus system with routes called links, which is why the transit system is known as Lynx.
A free downrown shuttle loop called Lymmo uses natural gas powered buses.