Thanko has given us much joy over the years, from e-cigarettes
to necktie / spy cameras
. But the Bluetooth Headset Wristwatch? Hell, this one looks almost useful: your watch can be popped out of the wristband to do double duty as a Bluetooth earpiece. Charging for two hours via USB will give you around four hours of operation, depending on whether you're using it to make calls or listen to music. Available in Japan for roughly $90.