I just made an eye-opening discovery: you can ADD "annotations" to your own videos on Youtube! Go and look at one of them, you'll see an option to "Edit video annotations" under "Video owner options". You can customize the size and vertical position, and the time each annotation lasts. ("Help" is easily available from the place where you're doing it.) For tutorials, I think this is pretty spiffy!

I tried it out on my Counter-Rotation video, www.youtube.com/watch and also on my Behind-the-back pass, www.youtube.com/watch