Alright, my time to try and contribute =)
Horde only btw (sorry allys)
Its quite simple really, get a friend with a mechano hog to meet you at Sen'jin village in Durotar. Jump into the passenger seat of the bike and have the driver of the bike talk to the witch docter at Sen'jin. The witch docter will hex the driver and flip the passenger seat upside down. After the hex goes away the passenger will still be upside-down and eating dirt. =P He will remain that way until the driver dismounts. Its funny how many comments you get when your drive to orgrimmar. =)
The passenger can dance in the passenger seat upside down and what-not. Be creative.
Anyways, have fun!