Remember the Weasley family's clock from Harry Potter and the Chamber of Secrets? If you're not familiar with one of the most useful pieces of wizarding technology, I'll clue you in: the clock had a hand assigned to each member of the (large) Weasley family, which would point to different areas of the clock's face to show where the person was at any given time, i.e. home, school, prison, and so forth. Get ready to be super jealous, because a brilliant Harry Potter fan who goes by tbornottb3 on Reddit has built a working Weasley clock, presumably using magic.
OK, fine, I guess it's really more of an engineering marvel than actual magic, but I personally feel like I could probably produce a Patronus more easily than build this thing, which tbornottb3 described as "really just a Particle Photon connected via a breadboard to an addressable LED strip." Oh, is that all?
He started with an old clock found at an antique store, then laser cut a new wooden face. The clock is connected to the web service If This Then That, which communicates with the family's phones to locate them. The family simply defined a radius for each area, such as work or school, plus some fun twists; crashing stocks cause one family member's digital "hand" to slip into "mortal peril," while a forecast of snow sends another to "holiday."
The "B" at the bottom of the clock signals an incoming update by flashing a different color for each family member. Unlike the Weasley's clock, family member's hands are actually light-up initials, and not pictures where they look absolutely mortified to be on a clock.
If you'd like to build one yourself, you can score a Photon (the Wi-Fi device that keeps the whole thing running) for less than $20, and tbornottb, aka Trey, is willing to share his code with you. He said that he started the project just after Thanksgiving and was able to finish it in time for Christmas. Redditors are already begging him to make a business out of this, but Trey, who's currently a computer science student at Duke, already has a job lined up post-graduation.
I've got to say, I feel really badly for all of his siblings now, because I can't imagine what they're planning to give their parents for Christmas next year. How exactly does one top a working Weasley clock? Enslave a house elf? Bewitch a Ford Anglia and teach it fly (and later go feral, and live in a forest)? At any rate, his family is one lucky bunch of Muggles.