Nice! I did the same thing a couple weeks ago <http://github.com/jackrusher/jssvggraph>; to help explain the simplicity of the algorithm to a friend. Mine paints SVG directly rather than using Raphael, so it only works with browsers that support that standard. One thing this brought to my attention is that the WebKit SVG implementation is much, much faster than Gecko's.
For this demo I was really focusing on simplicity and getting the basics right. I just wanted dots and lines but was too lazy to figure SVG DOM manipulation. Raphael makes it really easy.
