You let your phone manage your contacts, appointments, and even your health, so why not let it manage your relationships, too? Pplkpr uses GPS and a heart rate wristband to determine your emotional state around specific friends. As a result, it can tell you who makes you the most anxious, the most excited, the least bored, and so on, giving you a better idea of which friends you should maximize your time with and which friends you might want to make less frequent appearances in your life.
A good rule for accessorizing: if it doesn't do something functional, it's probably not worth wearing. The Wrist Ruler is a perfect example. Resembling a plain leather bracelet from afar, it actually doubles as a ruler, with laser-engraved inch and centimeter markings and a handsome silver post. Individually numbered and made in small runs in a Portland, OR workshop.