You will need to upgrade to OS X 10.4.9 or higher, or download and install 'ichatUSBCam' at this link... http://www.macupdate.com/info.php/id/12294
10.4.9 and 10.4.10 will recognize the cam natively.
All the cool features like snapshots, auto-focus, face tracking, etc... will not be available without the PC only software. I contacted Logitech about the auto-focus not working and they told me that the Pro 9000 has internal hardware that requires software control.
I have found the focus to not be a problem as almost everything is in focus anyway.
This cam is very sharp, very high resolution and auto-exposure and color balance seem to work great.
Hope this helps,
Oct 4, 2007 5:30 PM
Logitech 9000 Camera Software
This is the Logitech Webcam 9000, as recognized by OSX. Click on Input on the Right Pane; In the format dropdown, select a different Hz from what is already selected. Now in the Volume Tab right under the format dropdown, fiddle with the volume bar, decreasing it all the way and then increasing it to the max. And now your microphone should work again. You don't need a driver for Logitech Webcam Pro 9000, it is a UVC camera and works by default on Mac OS X.