Many of you probably know that, for some reason, iSight cameras can get into a weird state where they start causing serious errors with FireWire drives.
The symptoms usually include a bunch of I/O errors while copying to a FireWire drive: failed copies, flaky behavior, crashes. All of this goes away if you power off, disconnect the iSight, wait a while and power back up.
Sometimes, the iSight stops working with iChat (it says the camera's in use when it's not, or the light comes on, but you don't get any picture), and in it was in that second state today when I had a kernel panic.
No data was lost, I'm happy to say, but I decided that I've had enough of this. Since 10.4.9 supports USB cameras, I've switched to a Logitech QuickCam Ultra Vision. (All they need to do is add Super Deluxe Extreme Edition to the end to make it really cool!)
It's not as elegant as the original iSight (it's fixed focus, horizontal format, a bit gaudy), but it's got a nice wide angle lens, built in microphone, works with any monitor, and seems reliable. Plug the thing in, and it works.
Given that you can't buy "real" iSights any more, and based on direct experience, I give it a thumbs-up.
Sorry, iSight. I'll miss you!