This thread has been inspired by the "fly in Isle of Quel Danas" below, however it is different.
What it allows you to do - fly ANYWHERE in old world. Yep. Anywhere.
How to:
(Kalimdor):
Step 1 - fly anywhere in northrend
Step 2 - queue for random dungeon
Step 3 - port inside
Step 4 - teleport to moonglade
Step 5 - you are in flight form in moonglade. Enjoy.
(Eastern Kingdoms):
Simply take a boat or zeppelin, just make sure you are flying "above" rather than standing on top of it.
Screenshot:
ENJOY BEFORE ITS FIXED!