Oh Harry Potter, you may be the stuff of fantasy for kids everywhere but you're not real. Which is why Twitter  is more awesome: It's really real, and someone's just used it to make a version of the Weasley family's locator clock.
If you don't remember the Weasley family's magical Whereabouts  clock from the Harry Potter series, here's a quick reminder: It doesn't tell the time, but it does have nine hands (one for each family member) that track everyone's location in real time. The dial has Home, School, Work, Traveling, Lost, Hospital, Prison, Quidditch, and Mortal Peril engraved upon it, and as Lord Voldemort's evil power expands more and more time is spent with the hands pointing to the last one in that list. It's magical, unique, and sadly fictional of course.
Enter Twitter, and a nimble-fingered DIY Arduino programmer. The premise is simple: Take the Twitter feed of each family member every couple of minutes or so and parse the text for known locator-status words. Recognize relevant phrases, then pass control codes to a programmable Arduino board hidden inside a replica Whereabouts clock. Result: Individual's hands are driven to point to the relevant location on the dial, with a choice of Home, Lost, Texas, Traveling, Prison, Work, Church, Minnesota, School, Read Me, Doctor and, yes, Mortal Peril (though since G.W. Bush's power has waned, it probably won't point here often).
Simple, brilliant, soon to be turbo-powered  by the expected explosion in geo-located Tweets, and I really really want one.