Ever wanted to use your desktop as a sketchpad? And by 'use your desktop' I do mean quite literally! A reader by the name of 'Marko' dropped off a tip about the following self-described 'free painting software' that allows you to use your fingers, mouse or graphics tablet to make free-hand annotations on your desktop - no need to stay within the rigid confines of an application window or canvas any longer! Treat your desktop like a chalkboard! This is Ardesia.