Previously Google Visualization API use to support grapahics/charts for data only in Google Docs/Spreadsheets. That has changed…Google now supports any Web-based data source, including databases and Microsoft Excel spreadsheets! So basically if you have a database-centric website, you can use Google Visualization API to:

• Embed visualizations directly into your website,
• Write visualizations and also wrap them as Gadgets with the simple Gadget Extensions of the API,
• Create dashboards and reports over your own data,
• Write visualization applications for Google products such as Google Docs,
• Use as many datasources you want, but just using one API !!