Glyph of Zen Flight can be used to train your monk to use Zen Flight, which has many distinct advantages. Once you have the glyph, make sure it is installed in both of your specializations and the spell is available on an action button.
1. You can use Zen Flight while falling. It is instant cast and will prevent you from dying or taking fall damage.
2. You can perform many actions while using zen flight. Herbalism is restricted though, just as it is with a druid.
a) Fishing
b) Mining a node
c) mounting up, even on ground mounts (Of course, this means you will fall as soon as you are mounted.)
i) Side Note on this one, I have used a repair mount while falling, then used zen flight and watching the repair guys fall the rest of the way
d) Hearthstone
3. Interacting with quest objects, using a gear box icon.
NOTE: It is important to realize that if you log out while using zen flight, that the buff will be removed at that time, and you will be falling/dead upon login, so make sure to mount up on an actual mount before logging, unless you trust your ability to reapply zen flight before hitting the ground after your interface loads.
Also, it is good to realize that interaction with any NPC will cancel your zen flight (including entering combat, upon which you will be given a parachute). Zen Flight has the same restrictions as flyable mounts, and cannot be used in areas that you can't normally mount.