A simple, step by step tutorial on using the green screen capabilities of iMovie '09 on a Mac. I start with the set up of your green screen (I used bright green lycra, 2m for $50 from Spotlight), enabling Advanced options in iMovie and creating the green screen effect, with various examples.
Note: I manage to say iMovie '08 several times throughout the tutorial because I didn't check the version, so sorry about that. It's definitely iMovie 09 version 8.0.5 (820) that I'm using.