Dan Roam's "Napkin Academy"

The author of popular "The back of the Napkin" book,
inspired by "Khan Academy",
has created a series of educational videos called "Napkin Academy"
teaching us all to become great visual thinkers
Napkin Academy | Learn to solve any problem with a simple picture

One difference: it is not free. a few lessons are free

podcast: Interview with Dan Roam by Dr. Moira Gunn @ Tech Nation @ IT Conversations

New book: When Words Don't Work