Take a look at Jing – the “always-ready service” that allows you to instantly capture, edit and share images and video, from your desktop to anywhere. Jing captures anything on you see on your computer screen, as an image or short video, and lets you share it instantly.
This is free screenshot and screenshare software from TechSmith. You can take screenshots (capture an image of what you see on your computer screen) and record screencasts (record up to 5 minutes of onscreen video.). Students can use Jing to collaborate, or ask questions. Faculty can record feedback while grading papers, or take a snapshot to share with class.
Take a look at the Jing Project Blog (where you can ask questions, give feedback and share how you use Jing) and check out the Education Community Blog (tips on using screen capture and recording in all aspects of the educational landscape, and sharing stories).