You can now add video to the descriptions of your events, exhibits, sites, museums, and organizations. Here's how Old Sturbridge Village is using it to bring to life their annual Redcoats & Rebels weekend, the largest Revolutionary War reenactment in New England.
To embed video content from YouTube or Vimeo, or content from other media hosting sites, such as Scribd (document hosting) or Flickr (photo-sharing), click on the new "Source" button, as shown in this screenshot, and paste in the embed code provided by the site hosting the content. (In the case of Flickr, you can use one of the handy viewer widgets, such as the free PictoBrowser.)
An example of where to find the embed code is at the bottom of this post.
The partial screenshot below shows the code to embed a YouTube video. The other hosted media sites are similar. Look for a "Share" or "Embed" button.