You microchip your dog to keep him from getting lost, so why not microchip your lady too? With jewelry that is. These interesting pendants from Aerogem are made from onyx or sterling silver and have a hand painted microchip in the middle. The microchip is purely decorative as far as I can tell. Although if your girlfriend or wife is a paranoid conspiracy theorist, these might not make the best gifts for obvious reasons. For any other geek girl, they’re a playful yet pretty nod to technology. Aerogem also sells jewelry made of Aerogel which is some crazy synthetic super light solid material that looks like smoke but is solid and made by extracting the liquid component of a gel.