This Nokia concept is made of memory plastic that can be molded to fit around a wrist, for example, then can be heated to return to it's original shape.
This pen phone is one of the thinnest and smallest phone designs yet. While it's designed to be connected mainly via a bluetooth headset, the top and bottom of the phone do include a receiver and earpiece.
NTT DoCoMo's prototype "wearable terminal" brings us one step closer to being cyborgs. You stick your index finger in your ear to hear and speak through the microphone at the back of the wristband, then snap your fingers to connect or disconnect the call.