I’m going to spend more time thinking about integrating mobile/GPS applications into websites like NJ State Atlas. I might try making a Smart Growth Locator that performs a lookup on where you are currently located. One of my longer term goals would be to create some sort of social networking site that is based on the National Grid. The Grid would allow you to handle proximity and fuzziness in a way not currently offered in other location-based social networking apps.
John, blackberry is definitely a better platform for Geo/LBS apps than most of the other phones in the US market. Unlike iPhone, you can also do most of your location tracking in the background.
We have built a service called http://www.mygeodiary.com which enables users to record, organize, annotate and share their geo tracks with any site on the web. We also provide support for various GPS devices including a blackberry GeoRecorder software which let’s you record and annotate your tracks with photographs and upload them them directly to your geodiary account.