I believe I've found my next project. It appears that the NFC Ring is about to hit the streets. There's a bowl on my dresser where I toss my keys, pen, and whatever else is in my pockets, when I arrive home. I'm thinking that I could marry a Raspberry Pi, a NFC sensor, and a NFC Ring, so that the action of dropping the ring into the bowl (or other container) causes the lights in the office to come on and a WOL packet is sent to the computer. Inversely, removing the ring from the bowl should ensure that the lights are off (after a certain period of time).
I got the above idea while researching NFC tags. I'd seen a project where someone drops their phone into a bowl that has a NFC tag in the bottom, at his home, office, and gym. Each of the tags causes the phone to change settings, join Wi-Fi, etc.
The ring project looks a bit more attractive in that I only need it at one location and the charge on the phone remains an issue (can barely make it through the day on one charge). What'd'ya think?