I've not posted anything since ever and I've been a member longer than most people.
Here's a video of glitching under Orgrimmar, I searched and searched and could not find a existing tutorial for 4.2 without the use of third-party programs.
This video is not by me but I've found it very useful; from Org you can fly under everywhere up to; but not limiting, The Infamous GM island. Just remember to stay low.
(I know this thread could be considered a Guide( as with almost 70% of the exploits) but since it isn't allowed nor common knowledge, I thought I would share it with you.)
Mats: Flying Mount, Medium-Large ground mount, be Horde (Alliance is possible if you want to, you can also be pretty annoying to horde and summon your Guildies if you want to create some real confusion.
SO the guide!.
1. Go to the Cleft of Shadow(s) (More commonly known as the dark place, entrance to rfc zone, rouge zone, etc.....)
2. Fly up to the Northernmost (Northwestern most is also easy) bone support/ Rib
3. Stick your character in the crevice between the bone and the ceiling.
4. Mount up on your Medium-most(I.E. bear/Kodo Ground mount (Flying mount acceptable too, but you can easily fly through both walls and and up in the Valley Of Spirits.)
5. 1 second before your cast finishes jump forward ( personally I keep spamming jump from here because it can force you through.) once you get in walk/mount and fly/fall straight down.
6. Mount on flying mount( and walk towards the opening you can see (dont fly becuase this opening is acutally the entrance to rfc and you will zone in if you fly too high.
7. Get behind AH
8. Get under Bank with all that gold and /dance
9.??
10. PROFIT!
(8 could be considered 9)