I was recently working on finding a reasonable webcam that would work with an Intel Mac Mini, since Apple no longer sells the iSight and the prices for them on eBay are outrageous.
After reading reports that newer versions of the Logitech QuickCam Pro 5000 (labeled as "Vista Ready") worked on Macs, I picked one up and tried it out on my Intel MacBook laptop, running OSX 10.4.8 at the time I believe.
Despite what I had read on various postings, the camera didn't show up at all, although the built-in microphone worked OK, appearing as something like "Unknown USB Audio Device". The camera worked OK in Windows, so I figured the hardware was OK - and returned it to the store and started looking again.
After a while, 10.4.9 came out, and supposedly included updates that supported more webcams. I bought another QuickCam Pro 5000, and this time found that the camera and microphone worked in iChat, but the version of Skype I had at the time (18.104.22.168) only saw the microphone.
I figured this was good enough and took it out to the person with the Mini. While there, I updated OSX to 10.4.10. When I plugged in the QuickCam, I found that the camera worked, but now the microphone didn't show up at all. When plugged into my 10.4.9 laptop, the camera and mic worked fine. Apparently Apple broke something in the 10.4.10 update. (there's a discussion of it here.)
After poking around, I found the AppleUSBAudio system extension, which seemed like a likely suspect. By replacing it with the same extension from 10.4.9, I was able to get the mic working - it went something like:
sudo -s (type in password) cd /System/Library/Extensions kextunload AppleUSBAudio.kext (backup the AppleUSBAudio.kext directory somewhere else) (copy the 10.4.9 AppleUSBAudio.kext directory to this directory) (permissions got changed moving between machines, fix that up) chown -R root:wheel AppleUSBAudio.kext kextload AppleUSBAudio.kext
Plugged in the webcam, and now both camera and mic work. Tried a newer Skype - 22.214.171.124, and that works too.
So I think we'll be able to chat between the Mac Mini and the MacBook for a while - at least until Apple updates the OS again.
In a followup entry, I replaced this camera with a Logitech QuickCam Communicate STX.