It will be great if the wiimote could track the distance between the tip of the IR pen and the screen, or the distance between the tip of the IR pen and the wiimote to increase the size and decrease the opacity of the brushes just like an airbrush. The wii whiteboard can sen this information to softwares with pressure sensitive, like photoshop and gimp.
I'm using the wiimote whiteboard in my linux ubuntu 8.04 to do my professional work (I'm an animator).
It is impossible to determine distance with only 1 LED, sorry