This has been tossed around frequently under
mask lanyards.
A simple piece of paracord off the backstrap, brass mini clip, neck bungee (which is also used for the safe second.
Most people resist it until they try it. Or until the CPO instructs them that this is how it shall be done.
Here's an amusing story of the day I fixed the prototype of your mask with a kitchen utensil:
Myspace.com Blogs - The Heads Up Display Mask, the Oceanic HUD... the back story - SCUBA MySpace Blog