ShareThis
The ShareThis plugin provides a simple way for users to send a link to your post via email or AIM and to add your post to many social bookmarking sites, including Facebook, Twitter, del.icio.us, and more.
Screen shots of the ShareThis plugin
From icon to widget
Alex King’s efforts to standardize share icons back in 2006 has now evolved into one of the Internet’s most prevalent widgets, operated by the ShareThis. You can customize the ShareThis widget on your site as well as register for a dashboard that will track share events and provide reporting. For those who want a localizable version or do not like using widgets, the ShareThis Classic plugin is still available.
Customizations and reporting
You can customize the ShareThis widget on your site so that it blends in. You can add it wherever fits best, but it can also be automatically added to the end of your content area. Plus, if you associate your code with your ShareThis account, you can review detailed activity reporting.