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)
Looking Ahead to Tcl 8.6 Jeff Hobbs http://www.youtube.com/view_play_list?p=8E2B4FE4AB6A5B68 (playlist of 3 videos)
Tcl/Tk is used for a BSD network diagnostics tool.