I liked the way the whole class could see what was being explained / demo'd / shown by the teacher as it was projected onto the board via the class projector. I also thought I could use one to record drawing skills to add to the online "mooc" style that I have been using to set up my class website.
I decided to recycle one of the class drawing boards and with the help of part of a wooden handle and a small piece of scrap wood, I managed to spend less than $20. This was spent on a webcam to transfer the video across to a computer.
This worked really well using Quicktime. I chose "Mew Movie Recording", then this works for both uses. It shows on the computer screen what the webcam is seeing, so this can be projected onto the board via the class projector. There is also a record button so you can record what you do with the students or prepare one earlier to put on the class website.
Here are some very quick experiments I made today to test it out.
Test 1 - normal quality with no extra lighting.