Now I've probably missed the boat on this one ... wouldn't it be amazing if phone companies opened up GPS locations.
To be able to program programs effectively for a given environment would take personalization to the extreme. Look at how the web has developed allowing communities to form to develop software. Now there is alot of ethics in this that would come into play such as authorization from the end user.
Currently there are companies offering limited services, just think if this sort of service was opened up to other institutions. For example a class field trip where we could produce certain materials for a given environment. And let people explore. Or audio files which kick in for tourist attractions, like they do just now with the tape and headfones.
With the ifone we can now program ourselves new integrated services.
By the way if this is already out there, make a comment as I would be interested to see what is being done within this area.