This bug will let you fly in the air, you can cast, mount, turn around and in general do anything except for moving & strafing. I have not tested with a mage yet but I will do this and make some portals high up in the air
Its the most fun with travelers tundra mammoth since you can bring two passengers and drop them off, if you drop them off inside a mountain (when you fly through one) they will fall through the world and have to ress at a graveyard.
The bug is done by moving backwards while a zeppelin flies or crashes into you, this will make you get stuck to the zeppelin for as long as you like. It breaks upon moving or zoning so I prefer to use the one between Orgrimmar and Thunder Bluff.
My way of getting the zeppelin to crash into me is to make my character size large enough that I can stand on the ground below the zeppelin tower and and have the zep smash into me. I then turn my size back into normal and the result is seen in the picture below.
If anyone requests a video then I can make a video of this and upload to youtube by the evening when I finish work.
Edit: I added a movie:
[ame="http://www.youtube.com/watch?v=_lAIN7Gm4j8"]YouTube- flyingtundra_0001.wmv[/ame]