One of the cool thingsabout active digitizersis that they arepressure aware. Thedigitizers in most Tablet PCs can detect256 levels of pressure,whereas some of theeternal ones artists usecan detect 512.
While I was at TechEd Australia I had a cool sideline conversation with a chap from Wacom. My colleague Lee was with me at the time and be asked this guy if they had any little utils that could be used to show off pressure awareness in tablets. The answer was no, but we all agreed that it was a cool idea. I foolishly opined that it would be easy to make one, hence volunteering.
I'm still tinkering and will release code soon, but I'm using the real the stylus API to detect the pressure levels and render a circle where the radius is relative to file pressure applied.
Still a bit rough but the Gif below might give you an idea of what it looks like.
