flot
Attractive JavaScript charts for jQuery
... of the examples is probably the fastest way to learn how to use flot. Just include the JavaScript file after you've included jQuery. You need at least jQuery 1.2.6, but try at least 1.3.2 for interactive charts because of performance improvements in event handling. The plot function immediately draws the chart and then returns a plot object with a couple of methods. The placeholder is a jQuery object or DOM element or jQuery expression that the plot will be put into.