FYI - this format was popularized by Academy123 (a Los Angeles area startup that was acquired by Discovery Education).

They used Win32 software running on Tablet PC's and captured a teachers voice and handwriting in real time.

At their peak, they had about 400 teachers working from home creating thousands of 3-5 minute mini-videos each day.

See some examples here: http://www.nutshellmath.com/textbooks_glossary_demos/demos_l...