EXCELLENT reply! Ever see the movie "Water World"? I swear Kevin Costner was using compressed air as part of his catamaran system, and they even gave some hints with the vertical blade turbine usage. It seems sometimes TPTB give us little "hints" here and there about what is ACTUALLY in use but just not available to "mere consumers" just to throw it in our faces...
I have indeed heard of power companies pressurizing caverns for storing off-peak energy before, but can you imagine if they were using DiPietro motors to power the generators instead of the inefficient turbines? Combined with flywheels that actually store air pressure/weight and the entire grid could be powered by mere gentle surface winds and/or even the fluid movements through storm and sewage drains!
THIS is exactly the type of discussion I was hoping to encourage, THANK YOU! =D