The Wireless NEC P-ISM
These special pens project images of a keyboard and monitor on any flat surface. They are currently in development by Japanese manufacturer NEC under the product name P-ISM.
The only negative aspect of this invention appears to be that such small computers may be easily misplaced.
Implications - Though a pen-sized computer seems impractical in terms of computer-based activities, the convenience of an easily portable, multi-capable device like this one is undeniable. The projector pens are a crafty innovation that may potentially alter technological norms as we know them.