Of possible interest to this group.
I put together a quick little hack that shows how you can use IPython notebooks to incrementally build out interactive code samples to accompany recorded audio/video. It uses a Mozilla webmaking tool called popcorn.js which lets you set event callbacks for points in the media timeline.
It is kinda nifty - as it allows you to play with the code as the "instructor" builds up concepts.
pretty rough proof of concept at this stage - but there you go.
https://github.com/ptone/nbcast
-Preston