Problem right now is that SVG is being pushed as the client side graphing standard but no ones rushing to implement. The WHAT-WG and the other standards that attempt to incrementally improve DHTML also have a problem gaining traction. So what we have is a state where things are locked into the year 2000. Only improvement I've seen in DHTML pages in the last 5 years is Ajax.
In the meantime, you can always resort to [link|http://z.iwethey.org/forums/render/content/show?contentid=187774|drawing primitives]. Personally, I'd settle for a standard point and line primitives, with some rudimentary form of coordinate mapping. With those, I could construct classes to do bar charts, pie plots, cross plots, or any other form of shape or image.