Thanks to the brilliant new captioning software available on Youtube, I am going to make all of our videos deaf/hard of hearing-friendly by adding caption support.
This is currently already avaiable on Brian Fokker-Irwin, and is turned on and off as such: http://www.google.com/support/youtube/bin/answer.py?hl=en-uk&answer=100078
If you turn on captions, Youtube will remember you've done so and will display captions for all videos in future. You can always turn captions back off if you no longer need them displayed.