Why don't you watch the peepcode screencast, it's only 9 bucks but very worth it. He explains how to use iMovie, iShowU and Omnigraffle for creating them. The

Why don't you watch the peepcode screencast, it's only 9 bucks but very worth it. He explains how to use iMovie, iShowU and Omnigraffle for creating them. The link is https://peepcode.com/products/screencasting-on-the-mac https://peepcode.com/products/screencasting-on-the-mac (BTW I don't know or am affiliated with the top funky guy, just a fan of their peepcode screencasts)