There is a great post by Julian Bleecker on O'reillynet.com: A Design Approach for the Geospatial Web. The article summarizes the approach taken by the USC School of Cinema-TV's Interactive Media Division and the Mobile Media Lab to designed location-based experiences. Some excerpts of Julian's claim I appreciated:

This is where the concept of location awareness comes into play. Like most context design models, location awareness focuses on a user-centered perspective. More than simply knowing latitude and longitude, location awareness is meant to consider more subjective aspects of LBS design, such as: with what activity is an individual engaged? Are they looking to find how to get from point A to point B, or are they wandering about, engaged in social activities, or on a shopping excursion? (...) Finding one's location and mapping (and now route-finding) represent, respectively, first- and second-generation GPS applications. Location-based services that approach their designs with location awareness in mind will represent the third generation of locative applications. Of course, GPS will be used in this third generation, but it won't be up front and center in the design. Instead, GPS will enable location-aware designs that require location, proximity, and movement to be components of the application design.

Read the article it's plenty of other interesting dimensions.