Google Chart Wizard
I just discovered the Google Chart API the other day and found it to be incredibly easy to use. Within about 5 minutes I had a chart working the way I wanted it to look.
Have a look at the Chart Wizard to see what you can make:
https://code.google.com/apis/chart/docs/chart_wizard.html
It’s so simple to use, you call the API through the URL of an image, and that URL contains all the parameters for the graph.