OpenBoard - The OpenBoard software is an interactive white board software.
Surface Studio - A brilliant screen for your ideas, from Microsoft
Conceptboard - Instant Whiteboards for Teams & Projects
Twiddla - Mark up websites, graphics, and photos, or start brainstorming on a blank canvas.
Scribblar - Scribblar is a free online collaboration tool that is perfect for online tutoring.
WrittenUp - A free virtual whiteboard for remote collaboration