Every time my professor lectures, he will use his tablet PC and project it on a screen. Then he starts a series of blank power point slides, and instead of writing on the black board, he'll write on the blank power point slides instead. At the end of the lecture, he'll post those power points online. It's like I get to bring the whole black boards home for free!!! And even better, during office hours we can ask questions about specific parts of the lecture, and my professor can look it up online and knows exactly what our questions is about. I find this to be a very convenient and effective way of teaching.

...but the product page for ZoomIt is very well done