Crayon Physics Deluxe [ http://www.crayonphysics.com/ ] is a puzzle game rendered in crayon drawing. You draw objects on the screen and use these with physics in order to get your crayon ball from start to finish. My brother in law had the iPhone demo last year, which I remember trying and enjoying.
It is an indie game, and this weekend (until January 15, 2010) they are running a ‘pay what you will’ promotion (for the PC version). So go support creative talent, and draw up some fun today!