This is an example of a specially-tagged web page that contains a Flash video player widget and uses AddThis for sharing. View the source to see how it all works, or read an overview of widget sharing with AddThis.
This page contains special tags that identify the widget so AddThis and others can locate it (view the page source to see them). These tags specify the URL, height, width, and other content properties.
This is a YouTube Flash player embedded with a simple object tag:
When AddThis shares the page to a destination that supports Flash widgets, it will locate the video player and share it along. Share it to iGoogle to see this in action: