Found a link from here about a little package available for the iTouch called Brushes. It's got a surprising amount of control and usability for such a simple program and I had my first go yesterday lunchtime. Just have to get used to using my fat digits instead of a pencil.
It probably looked like I was playing quake rather than the high art that was going down.
Need to do some proper colour studies and more experimenting - I will post all my abject failures up here of course!
Starting with this one.
