ShareThis is a widget for posting and sharing websites to several popular social networks, social sites and email contacts. In addition to Facebook, MySpace, Digg, Delicious, Reddit, StumbleUpon and many others, users can now easily submit sites to FriendFeed and Sphinn.
You can see it in action at the bottom of all my posts, courtesy of the ShareThis WordPress plugin (there’s also a JavaScript version available). A tip for WordPress K2 users, make sure to turn off Advanced Navigation when using ShareThis.