From time to time I need to talk about mathematics with my advisor remotely. I would like to approximate writing on a blackboard together as closely as is reasonable. What are some technological options I have for doing this?
It would be nice to do something similar to http://www.youtube.com/watch?v=qbCZbP6_j48, though it would be much better if it can also be done in realtime.
Edit: This question was edited in order to meet the exacting demands of the MSE Community Standards. I have borrowed a suggested phrasing from here.