Save your money on screencasting apps by using Keynote on your MacBook Air.
1. Prepare your slides in Keynote.
2. Under “Play”, select “Record Slideshow”.
3. As you speak, use the arrows on the keyboard (instead of the TouchPad) to reduce noise.
4. Once done, under “File” select “Export to”, and then “Quick Time”.
5. Upload the video into YouTube.
Yes, it is that easy. Here is what I produced last night, on how to create digital student portfolios: