I remember about 12 years ago trying to use a chat room on my website to help a student with homework questions. That frustrating exercise was probably the only time I regretted having an eager learner in my class.
About seven years later a former student contacted me on Facebook and asked for help with some derivatives. We exchanged comments about each step back and forth on his status. It was just as difficult as the chat room, but at least he can refer to it still if he would want to. (Can you believe that somewhere disk space is devoted to all those Facebook comments?)
Well, now us math teachers have something that will suit our needs better. A colleague in one of my courses pointed out this site to me as one she uses when tutoring students over the internet.
So far I have only tested this with my wife to see how easy it is, but I really like the possibilities. Accounts are free. Yes, there's still the old fashioned chat room feature, but you can turn on audio and talk directly through your computer's microphone. Best of all, though, there's a "whiteboard" space where all participants can draw or write anything. You can even turn on a grid for graph paper.
I'm passing this on to the math department in my district. Please let me know if you find this useful for long distance tutoring.