Collaborative white board

Can I use megascopes as an on-line collaborative whiteboard for purposes of holding a discussion about mathematics? In other words:
(1) can more than one person share the same drawing space?
(2) is there a drawing tool

I've been looking at the math symbols available with Megascopes, and I am pleased, but I need to be able to share it and add freehand annotations, like you can with Twiddle, the collaborative drawing board.

Thanks.