Recently Laura (pingVision's President) mentioned a screencast tool she thought might be helpful in developing video content.

Screencasting is a terrific way to engage in online demonstrations, allowing for a more engaging experience than using still shots. I have used tools like SnapZ Pro, which work quite nicely, but most tools require that you capture your screen actions, your audio, and/or your video seperately and then edit them together using something like iMovie, Adobe Premiere, Final Cut, or Avid.

Vara Software has developed a tool called ScreenFlow that melds all capture and editing into a simple-to-use software package. ScreenFlow not only captures your screen, video, and audio but during editing allows you to zoom, pan, and highlight portions of your screen in a fairly intuitive way.

I was able to download, video, and export a short screen cast in a very short period of time (the production quality leaves much to be desired) including one zoom in on an important section on the screen. ScreenFlow used the built in camera on my Macbook Pro, but you can choose to use an external DV source if you like. However, if you have open slots on your desktop that you add PCI firewire cards, you can have as many camera as card slots.

Unfortunately, ScreenFlow is Leopard only--so PC users and those who haven't upgraded to OSX 10.5 are out of luck.

I'm including an example screencast below. Please forgive the watermark--it shows up on the demo version of the software. Also forgive the crappy production quality. I threw it together as a quick way to learn a bit about the software.