Here's a new project for you: make your own smartboard for $45.
Have you heard/seen what Johnny Lee can do with a wii remote? It's pretty awesome
His website does indeed explain how to set it up and provide the necessary software to make it work. I did notice in his instructions that it requires a bluetooth, so I suppose that's an added cost if you don't have one. But hey, you could get yourself a bluetooth device and use it as a tax write-off!
And if you think it's too complicated, there's a video out there showing a darling fourth grader who created this interactive whiteboard as his science project. If Austin can do it, you can do it.
I don't currently have a whiteboard to set this up on. Someone do this and tell me how it goes. Do it.