I found the most important thing to do is store the previous x and y positions of shape, so the next time the user moves the mouse, the shape being drawn starts from the last shape added. Coupled with a basic acceleration calculation, alpha channel + canvas texture and you are close to what has been produced for Odosketch. Conqusently some of the shapes created when your graphics.lineTo calculations are slightly out, produce abstract results like the following.

Click below in order to activate the Flash movie, and then click again to change brush colour.

Flash is displayed here

Always find the following line of actionscript code to be quite funny, like when do you need a random colour other then situations like these!?!

Math.random()*0xFFFFFF;