Bluetooth enabled pens are nothing new, but they generally require something like special dotted paper to function properly. SMK Corp claims that their new "Wireless Input Pen" is the first device of its kind to transmit characters written in mid air. Combined with Bluetooth, the pen utilizes a a built-in triaxial acceleration sensor to detect the position of the pen when characters are formed, then transmits that information to a PC.
To be honest, writing in mid air seems like more of a pain in the ass than anything, but they do envision it having some practical use in place of laser pointers during presentations. SMK is currently applying for a patent on this technology, so when we might see it available to the public is anyone's guess. [TechOn via Japanite via I4U]