We have been waiting so long for Google Chart API. Google has finally released Google Charts API, which returns a PNG-format image in response to a URL. Several types of image can be generated: line, bar, and pie charts for example. For each image type you can specify attributes such as size, colors, and labels.

You can include a Chart API image in a webpage by embedding a URL within an <img> tag. When the webpage is displayed in a browser the Chart API renders the image within the page.

The chart above is generated dynamically and displayed in your browser with the following code.
<img src="http://chart.apis.google.com/chart?cht=p3&chd=s:hW&chs=480x150&chl=Large Portion|Small Portion">
Go and check out the developer’s guide of Google Chart API now.

Requirements: No Requirements
Demo: http://code.google.com/apis/chart/
License: License Free