I just learned that PBS now has dozens of widgets, which they are calling "Activity Packs", on their website at: http://www.pbs.org/teachers/activitypacks/index.html
Here's one from the Social Studies area that is appropriate for Black History Month:
Notice that in addition to links to PBS content, there is an "Activities" tab at the top of the widget.
And if you want to add a widget to your website, you just need to click on the "Grab It" link on the bottom right. PBS provides the HTML code formatted for a variety of social networking sites-- simply click on the appropriate button and log in to your account. Or, if your site is not listed, the embed code is easily copied with the Copy button.