Microsoft researchers, from their Cambridge office, have developed a prototype of a 'family tracking' clock inspired from the pages of Harry Potter, more specifically, Harry Potter's best friend Ron Weasley's magical family clock.
The fictional version of which tracks family members with each of it's hands representing each family member and pointing their locations, such as "Work," "Mortal Peril," or "Lost".
Its real life counterpart will use GPS technology to pinpoint family members' locations. The device has already gotten a lot of attention while it was displayed at Microsoft's internal technology fair, Techfest, in Seattle earlier this month. Source