Screenr is a free web-based tool from Articulate that lets you create screencasts without installing any software. There is nothing to download, it plays on everything including iPhones and it is free.
With Reflection, for $15, you can now mirror your iPad onto a computer. This means you can use desktop screen-capture software to record, narrate, and annotate your iPad tutorials or simulations!
"Creating screencasts has been one of my favorite things to do when working with technology. I have used this to help teachers and students with troubleshooting or professional development. It's a great tool to demonstrate how to solve a problem or clarify a multi-step procedure. "