I just saw a really interesting article on GPS based podcasts in West-Sweden.
Volvo and the West Swedish Tourism office have developed a podcast app with which you could list to various podcast based upon your location. At the moment of reading, it seems to me a marriage between an audio tour, but in podcast format.
Because based upon your location, you can hear information about the nature or cultural interesting information.
The app should be available in May, just before the summer season in the region. When I get a hold on it, I’ll let you know.