WEBCAM

Whatever camera you get make sure its a firewire camera because that is the only kind that will work with macs.

http://docs.info.apple.com/article.html?artnum=306687

According this u can USB Webcams as well.

I recently bought a Logitech QuickCam Pro 9000, USB, and it works beautifully with Skype. Plug-n-play, with one change in the preference setting to start my video automatically. I Skype with PC folks and have had no problems. The down side is the CD is for PCs only, so you lose some functions like taking a snapshot. But then I wanted the video camera function not a picture function. Since there are no instructions (PC) I just plugged it into the USB port on the back of my iMac and trusted my Mac to do what was necessary. Yes, success!

Here is a URL for MacCam, listing support for many webcams that will work with various Macs and the OS needed, and whether you need their MacCam software. Several webcams are supported with the built-in-drivers on OS 10.4.3 and later without additional software. http://webcam-osx.sourceforge.net/