Here is a new way of organizing peer groups and your Friday evening out:
The ability to track the locations of people has a lot of other applications of course. As the tracking devices become smaller and cheaper expect to see parents putting them in their children both to protect their children from kidnapping and also simply to find out what trouble the kids are getting themselves into.
Another possible interesting application would be to manage affinity groups. Imagine a traveller who is cruising down a road trying to decide which night club to try out. If people registered with an affinity tracking service then a traveller could choose a club or restaurant whose currently present patrons fit some desired demographic profile. One obvious problem with such a service is that just because one person likes a particular type of person doesn’t mean that most who fit a desired profile will like that person in return. Look at celebrities for example. They are loved by all sorts of people who the celebrities would very much like to avoid. So a service would need to develop eligibility criteria that require matching of preferences in both directions before that person driving down the street would get a flashing light on their car LCD pointing them to a particular bar or night club.