Ask HN: I'd like to make a 30-second screencast. Where do I start?

So I've a product prototype that I'd like to pitch about in 30-45 seconds, in animation of some form. I'd love to have something along the lines of Common Craft's "Twitter in Plain English (see: http://www.youtube.com/watch?v=ddO9idmax0o), but the problem is I've very limited knowledge of Flash or other similar tools.

Where could I get help in working with someone on coming up with a 30-45 second short on the product?

And to all those entrepreneurs who've done this before...did you come up with the videos in-house, or was it outsourced?