Haven't done any showing off recently, so here's a dollop:
Very similar to the example I would imagine you've already seen,
albeit with numbers. Because it uses the text and shadow APIs, it
needs Firefox 3.1b2, Chrome 2b, or Safari 4b or higher.
HTML5 Canvas graphing for Firefox, Chrome, Opera and Safari:
http://www.rgraph.net (Updated April 11th)