When the iPad was first announced it seemed like it could be a great digital sketchbook... until I found out it lacked pressure sensitivity. I know a lot of people have shown off the drawing abilities of the iPhone/iPod Touch but as long as it lacks this Apple is pretty much snubbing artists.
This could be solved with a wireless pressure sensitive stylus with a capacitive tip. I think such a product would make digital artwork a killer app for the iPad.
This is pretty smart. I was thinking about cannibalizing an old Wacom and making a case for the iPad to sit in for drawing - your solution sounds more elegant.
Do the touch APIs let you look at the actual dimension of a finger press, or is it just an x/y coordinate? I mean, does the information come across as a circle or as total surface area lit up by the touch or anything? I don't know the tech behind the Apple touch stuff at all.