I looked n couldn't find a thread containing this info anywhere...
Using Cheat Engine:
Address for "outside" state for WoW 2.4.1:
Change it to 0 and you can mount anywhere (tested on many pservers). If indoors, your character disappears, so as to be "outdoors" I guess.Code:[00C98474]+80 (Byte)
If you're having any trouble, this address seems related to outdoors somehow, change it to 0 also: (doesn't have any effect for me though, this value changes even when not logged in)
Don't get your hopes up though... I don't think that last address does anything!Code:[Wow.exe+0053435c]+80 (Byte)