There's been a cooler version doing the rounds on the YouTube circuit, but I still think this is pretty good

The brochure spiel:

With Capax's virtual whiteboard projector pen, you can write, draw, highlight, point, demonstrate and control all your mouse and multi media functions on SCREEN. Any wall or screen can be transformed into a virtual whiteboard or touch screen. Increase audience engagement with the ingenious REMOTE laser pointer cursor. Be free to walk about while presenting and controlling your computer without having to be infront of your computer.

The pen: