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

http://chart.apis.google.com/chart?cht=bvs&amp;chs=350x200&amp;chd=t:100.0,81.0,70.0,<br />64.9,43.3,39.3,27.5&amp;chxt=x,y&amp;chxl=0:|BBL|KTB|SCB|K|BAY|TMB|SCIB|<br />&amp;chxr=1,0,1553283&amp;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.