In the olden times of CD-ROMs, people were pretty excited about video interactivity and by this I mean being able to let people make selections on screen while a video is playing.
Thanks to Google's acquisition of Omnisio this summer, you can now do easy video interactivity using these features on YouTube.
Because they call it video annotations, a lot of people might miss out on how exciting this feature can be. (Annotations makes it sound like a homework assignment footnote or something.) But it's way cool, as you can see in this here video:
Want to know how to use it yourself? Get started here:
For more specific instructions, see the YouTube Help page for Video Annotations. I wish they had their own how-to video about using these features, but...for better or for worse, the way of YouTube HQ is to let users make the how to videos about their features. Viva la community.