http://www.ifans.com/forums/showthread.php?t=132024

Want to create a drawing app? Here you go. Clearly, you will need to make improvements to the drawing code, as I literally spent five minutes making this to test something for another app. Regardless, you should be able to get the gist of what's going on. What I am linking is just your basic standard xcode view based project. The only pertinent part of this are the touchsBegan, touchesMoved, and touchesEnded methods, which I will be posting in this thread.