This page collects videos about Tcl/Tk from across the web, from streaming sites like youtube, to simple downloadable video links.
Self-reload, a walkthrough of how to write code live using the interpreter, and end up being able to use eval to reload your own code, on the fly http://www.youtube.com/watch?v=hQcZE2b_pDE
Mathematics based sounds through block editing, demo http://www.youtube.com/watch?v=z1GaGO6zjbc (a bwise demo)