Have a glance at some location-based services scenarios in geo-community. It's a bit rusty and cliché, but it appears to be a good summary of what was expected in 2001. Applying LBS to people alwas tend to lead to safety applications. I think it's a pity, there would be more interesting scenarios (not only with game). Mobile learning would be a nice direction.

GeoModeTM (www.geomode.com) or miniature GPS technology can be imbedded into items of clothing and footwear to support child-tracking services i.e. “Tell me if my child strays beyond the neighbourhood.” (...) Other similar personal and commercial examples of people tracking, where the person being tracked provides tracking permission, can improve customer service and public safety.