Almost everyone has seen or read Harry Potter. One of the really cool things in the series is the Weasley Location Clock, telling family members where others are when they can't be found. You'd think that something like this wasn't possible without magic, but it is.
John McKernell's Weasley Clock is just like the one in the books and movies. It displays his location to his family members. This was done by replacing the brains of the clock with an Arduino fitted with an ethernet shield, which in turn was pointed at his mapme.at feed.
It's funny how the clock face is now used to display a location, analog style. We really like this way of masquerading technology. Sure, it wouldn't take much just to write an iPhone app to do the same thing. The benefit of the Weasley clock is that you can just tell by glancing at it where John actually is. If you are interested in creating your own location clock, check out his full write up over at his blog.