Hey MacMini2009,
Just wanted to thank you for bringing this webcam to my attention as I've been searching for a (relatively) cheap webcam for the Mac. I have an MBP docked to a monitor and keyboard/mouse serving as my desktop, so the built-in iSight was out of the question. I purchased the Rocketfish webcam locally after seeing your post and as far as I can tell it's a pretty good purchase.
It's a 2 megapixel webcam and the picture quality is pretty sharp with sufficient lighting. I haven't used it to chat yet, but I have tested that the mic works in iChat and other chat applications (via the audio/video setup windows). It's completely plug and play for the Mac (unfortunately none of the software provided works with anything other than PC) but having said that I've noticed that autofocus works without any additional software, and depending on the chat software you can zoom in and out manually. I think the face tracking requires a Windows PC though, but it's something I can live without.
I'm sure it would be compatible with iMovie '09. Again I haven't tested this but if the built-in iSight works for it then this should as well. All you would need to do is select the video and audio inputs as the Rocketfish instead of the default.
Hopefully this answered some of your questions. Most probably not very definitively, but I figured I'd contribute what I could as thanks for pointing it out to me. Any other questions, feel free to ask. And if you need, I can try making a video with iMovie (only have '08 tho) and let you know the results.
