Japanese SMK Corp. developed a Wireless Input Pen. The company showed the novelty at the TEXPO 2008 in Tokyo last week.
The pen has built-in triaxial acceleration sensors and Bluetooth.
SMK says that this is the world's first pen device that can transmit characters written in the air to a PC. SMK has filed patents for their wireless pen.
More details on TechOn. Via Japanite.