The Google Chart API lets you dynamically generate charts. To see the Chart API in action, open up a browser window and copy the following URL into it:
Press the Enter or Return key and – presto! – you should see the following image:
By just manipulating the URL parameters you can create any type of chart
Here is the complete API documentation
Here is a World MAP using the below URL
So can you create a Dashboard using this Google Chart API?
Yes. check this Dashboard Tutorial using Google API
What are the limitations?
It seems you can just encode an URL and send all the data to the chart API and it returns a PNG file of the chart image.
So basically it is just a Display only chart, I would wonder, if it would be possible to create an Image Map URLs and then link those to subsequent chart API calls for drilling purpose.
One big concern, and this could be a real show stopper for using this API for any kind of sensitive data
Since you are sending all the information into the API URL, Google has access to all the data points. Google says, that the data is kept in a temporary log for 2 weeks but should this be a concern for you?
There are lot of Dashboard and reporting options and this one comes straight from Google and its free. So give it a shot.