Maverick, via Channel 4, has been using Brightcove for awhile and has been given due recognition for their Embarrassing Bodies program.
Have a look at their online site and see how they incorporate video in their overall engagement and delivery of information to the end user.
They make great use of the broadcast episodes in the site and tie them very nicely into complimentary interactive widgets.
The use of video bridges the users from the television to the site and is a great first step to get them engaged in the online polls, surveys and other data collection feedback that then becomes part of the next show.
By no means do you need to have a television broadcast series to have something like this on your site. Adding interactivity to your site and video is a great way to encourage user stickiness and increase your potential ad revenues via higher CPMs.
Many of our clients are doing this by adding Comments and Ratings to the video player (have a look at Wired.com for example).
Others are building online presentation tools that sync up the video playback to other components of the page (think of a recorded presentation where the user can see a Slide component changing real time as the video progresses).
The best thing about this is that you can start small and build from there - try a straightforward addition of comments and ratings.
In the end allowing your users to interact with your site is a fundamental ethos of the web and that holds true for your online video.
Note: Do you have a great interactive use of video? Let us know about it!