Now, you can generate charts using Google Chats API. All you have to do is to enter this in your address bar:

http://chart.apis.google.com/chart?cht=lc&chs=200x125&chd=s:helloWorld

And then you will get an image that looks like this:

As simple as that! Anyone could just generate some sort of string to be passed to the URL and then output the image directly from their web application.