December, 2006, there was a blog-a-thon to commemorate the tenth anniversary of Carl Sagan's death. For my part, I posted a set of curriculum materials to support his classic work, Cosmos: A Personal Voyage.
Cosmos in the Classroom
The video series, itself, has since been posted to YouTube. So I connected links from the episode titles to the corresponding YouTube segments.
I plan to offer my AP students extra credit for watching the episodes and completing the corresponding assignments. (We refer to extra credit as "Credit Toward Final"--CTF).
Student instructions for Cosmos 101
I don't know if Cosmos is available through other web media outlets (Hulu, etc.). Someone will let me know in the comments.
UPDATE: Cosmos on Hulu is shiny. But it comes with "limited commercial interruption." Considering that the original broadcast was aired with no commercial interruption, watching Cosmos with commercials might be disturbing to some viewers.