Sneffel describes itself as a collaborative doodle pad. There is practically no learning curve to begin use. You man sign up, but it is not required. The product is in development, created by a young programmer attending University College London, who is interested in tools for education. He is open to suggestions also, so jut email him:
matthew@sneffel.com or use the feedback button on the bottom of the board. Sneffel is donation ware (young programmers DO need to pay for their education.)
After creating a 'doodle pad' you can just send the URL to partners. [
example] If you are working at the same time, you will actually see it happening in real time. Pads can also be embedded in a website.
Tip: Higher math teachers who are teaching how to solve difficult problems, use Sneffel. Create a step by step demo of how to solve. Embed it on a page or in a blog. Students can then go to it and hit the 'replay' button to see the steps worked out.