This is only useful for pvp and doenst work for pve.
Put this in a macro
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
/sit
/stand
Until all 255 characters are used. Then keep spamming the macro while walking forward and you will freeze up but still continue to function to everyone else. Everyone else will see you moving forward but be unable to attack you. Once you stop spamming the macro you will warp back to where you were.
This is nice for healer classes as you can heal and release the macro to go back where you first did the macro.