To do this you need a Traveler's Tundra Mammoth, or a 2 seater motorcycle.
1) Go to the Valley of Honor, turn right.
2) Stick your mammoth into the wall (See Below)
*Make sure the player is sticking all the way inside the wall*
3) Have the player log out.
4) Walk away, and when the player logs back in they will be under Orgrimmar.
Enjoy