This is not the first time Apple has toyed with the idea of using location to help find others around you. A patent filing for a concept application called iGroups surfaced last year. The patent describes a location-based service that would let members of a group locate one another using GPS coordinates. Group members could also use encrypted tokens to share information. The patent specifically mentioned trade shows and rock concerts, so this idea, if it ever materializes, may have limited usage.
It will be interesting to see what Apple may have in store for iOS in this growing area of location-based services. While many third-party applications use location information in novel ways, the core operating system and built-in iOS applications only scratch the surface of what is possible with direct access to always-on location information.