Google Chart API is an elegant way to generate nice graphs for the web, needing neither client-side (Java) nor server-side (e.g. Flex) add-ons. Reliability and latency are usually a concern with any off-site page element, but with Google both should be as small as you could get.
Above graphs are generated by calling
&chxr=1,0,1553283&chtt=Thailand's Commercial Banks by Asset
I’ve played with PHP solution like LibChart or ChartDirector, but using them still requires coding and the looks and feels are a bit 90’s, and Google Chart is not guilty of both counts. Of course, it couldn’t do nifty things like this, but it’s fast and free.
And there is a Drupal project in the pipeline (part of GHOP). The natural extension would be a Google Chart View for views module, and I’m sure that will come soon after. I’m just excited thinking about the possibilities this gives to both Drupal admin interface and Drupal-based sites.