Jing

Jing is a web 2.0 tool that would be great for any classroom teacher. This cross-platform screen casting program can be used for creating tutorials, screenshots, and much more. You can easily share anything you do in Jing on the web, email, IM, Twitter or even your blog. You can take a picture or make a short video of what you see on your screen. Its extremely simple and can eliminate phone and email time. The best part is that you can download it for free.
Any teacher could utilize this to clear up directions or even introduce a home work assignment over the Internet. A teacher could also be showing this on a projector or smart board while walking around the class room helping any kids. Also, it saves the teacher from repeating directions over and over again. If you record it once, then every individual student could watch it as many times as need and on their own time. I could definitely see myself using this in my classroom.