I just came across this new site (beta) that lets you create art w/ brush strokes and records the whole event as a movie. Then w/ a click of a button you can email it to your friends and even "frame" it to display in their online gallery.
I feel this would be a fun resource for art teachers to use w/ their students to help introduce proper techniques. Also, it has a well defined "tip" section w/ a huge gallery of online art to explore. For more info click here.
Check out my computer example (it's great that you can control the settings to create a time-lapse effect)