Audio Kiosk

The New York Times article on podcast museum guides portends a new cottage industry - the audio kiosk.  I see pushcarts and kiosks in urban settings selling audio guides cheaper-better-podder than the official museum guides inside.  For those who plan ahead, the downloads should be available.  Is this an iTune spin-off waiting to be spun?  In a lot of cases the demand for the guides is there but the supply is not.  On my recent trip to Nashville I would have paid for a download of guides to the city and to Vanderbilt University.  Who is stepping up to fill the demand?