One of the technologies that I discovered earlier this year is Google Charts. The API is brilliant allowing web developers to have a free charting framework at their disposal without a lot of work.
I used Google Charts in an older GMaps Plugin sales demo where I nested Google Charts inside of a map Info Window. I started down the path developing a simple Xcelsius model for generating the URL syntax. I stopped this process when I showed this to my development team who advised that this goes against all of the work we have done to lock down GMaps Plugin to meet the strictest security standards.
While we have made a conscious decision not to formally promote Google Charts for use with GMaps Plugin, I wanted to share the work I did through my blog. I advise that you review the Google Charts API docs and investigate if your corporate security policies will allow you to use this technologies. If so, you can couple this with GMaps Plugin or any other HTML compliant framework.
This example provides a working example of the Google map, a URL that you can plug and play into the Google Map label, or just the chart URL by itself. I also provided the source files for the tool itself in case if you are interested in learning how I put this together.