This extension for Magento adds a set of ShareThis.com buttons to the products page. It also includes two widgets. One widget displays the standard set of ShareThis.com buttons, and the other displays the newer “sidebar” set of buttons.
Download the Magento Connect install package here: Techninja_Share-1.0.1.
If you’d like to look at the code involved, you can download a zip file package here: Techninja_Share.
Check out the extension on the Magento Connect site.