Why hang on to your emotions when you can wag them proudly with a robotic mood tail? Sure, you may never have asked that question yourself, but intrepid DIYer Wei-Chieh Tseng seemingly has, and he's done something about it. Apparently, the tail makes use of the ever dependable Arduino and an RFID reader to detect different emotion cards that set off varying degrees of tail-wagging, or you can simply control the tail yourself using a Wii nunchuck -- because, why not? Did we mention there's a video? Check it out after the break.