This iNecklace ($75) by Adafruit is a fun way to show off your geeky tech side. The aluminum necklace features a pulsating LED pendant reminiscent of the Apple "breathing" LED on Macs. Before you wear it out, just pop the battery in and the LED will gently pulsate for up to 72 hours. And even better geeky news? The iNecklace is completely open source! Watch the video below to see it in action.