I once saw a similar and much larger community canvas whose location I have since forgotten. Several months later I got to thinking how it was made. I had and idea of using AJAX, so I whipped this up using just that to see if it could be done. That, in a jiffy, explains why I made this.

So what is it? Community Canvas allows you to draw by colouring in squares. As you draw your changes are saved for all to see. Also, as others make changes the changes will propagate to your canvas, even as you are still drawing! So go ahead, try it out with a friend.