New York Times has an article about using cellphones as travel guides in Japan:
If you stand on a street corner in Tokyo today you can point a specialized cellphone at a hotel, a restaurant or a historical monument, and with the press of a button the phone will display information from the Internet describing the object you are looking at.
The new service is made possible by the efforts of three Japanese companies and GeoVector, a small American technology firm, and it represents a missing link between cyberspace and the physical world.
I still think that free software and free, wiki-like content is the right way to implement positioned services. Anybody can populate data to Geonames and Wikitravel, making the groundwork for much richer information resources than a proprietary database can be.
Via Boing Boing