Hey there! I found your site courtousy of some peeps over at conceptart there's lots of praise for your awesome tools here.
I recently bought myself a Wacom Bamboo Capture tablet, and I have been drawing on it for less than a week. I came here today and used your classroom 30 minute session of dog drawing. What fun it is! Though, I wish there were some more dog photos. Maybe some face shots, etc. If you need any photos, I have a very photogenic dog! ;)
Anyway, it was really fun using your tool, and I really felt like I was in class again. I loved it.
And random off topic-ish question.
After drawing, ever, does your drawing hand shake? Man, this has been happening to me a lot lately. I think I hold onto my pen with a death grip or something!