How Would You Like to Travel 760 MPH on a Cushion of Air?

The co-founder of Tesla, Space X and PayPal has a new idea for high speed travel.  How about a tube that would squirt folks through it at more than 700 mph?

Elon Musk is proposing this very thing for the 380-mile distance between Los Angeles and San Francisco. The technology seems to be most efficient to destinations less than 1,000 miles away.