If this one makes it through all the filters, you’ll love the site. Here’s an example of one of the posts: http://demogirl.com/2008/01/11/how-to-remember-the-milk-in-gmail-and-google-calendar/
Molly McDonald is the voice behind all the screencasts you’ll find there. The perfect voice for it. Check out the about dg page to see the microphone she’s using.
Spend some time in there. You’re SURE to find a demo of something that will be JUST what you’ve been looking for.