When Fantasy Inspires Science - the Whereabouts Clock

It's not unusual for fantasy to inspire science. After all, deciding to undertake scientific research takes some imagination and a lot of "What if?" questioning. Even so, it's not every day that a project so closely mirrors the stuff of daydreams as the Whereabouts Clock, designed by Microsoft Research.

The "clock," currently a prototype, displays location information for every person in a family. Using cell phone information, the clock displays whether a given family member is home, at school or at work, as defined by the family.

Does this sound familiar to you? If you're a fan of J.K. Rowling's "Harry Potter" books, it should. Mrs. Weasley has a similar magical contraption in her house. Described as being similar to a grandfather clock, the magical version could display the location and well-being of each family member, including the status of "mortal peril."

The Whereabouts Clock is pretty cool, but I think I'd still rather have an invisibility cloak... or maybe a Nimbus 2000.  What Harry Potter gadget would you invent if you could?