I’m not sure if this is a just a PowerPC Mac thing, or a Mac thing in general, but it seems that they do not play nice with USB webcams. Not that I’m a webcam fiend or anything, but I have one, and it’s occasionally fun for taking goofy pictures with. It’s a Logitech Quickcam Chat, the older blue and white version. (The one in the link is not the exact one I have, but it has the same name so I’ll assume it’s an updated version. It’s very similar to mine, though.)
Anyway, I decided that there HAD to be some kind of solution to this since I have Leopard now, and Leopard has Photobooth, and Photobooth is all kinds of ridiculous fun. So I went on a Google hunt. And after much Google hunting, I got it going.
Here’s what I did:
1. Download macam: macam is an independently-created USB webcam driver for OSX. Grab yourself the proper version for your version of OSX and install. It’s easy. After that, open up the macam application and test it out. If it works, great. If not, I have no idea what your setup is and I can’t help you.
2. Download iChatUSBCam: iChatUSBCam is another USB webcam driver for OSX, but this one is specifically for iChat. It’s shareware, and I’m still on the trial. Now, I didn’t do very extensive testing or experimentation here, so I’m not sure if it affected anything other than iChat (which was the problem I was trying to solve since I basically never use iChat anyway) but I know it works for iChat, at the very least.
3. Start Skitch: This one, I can’t help you with. Skitch is still in an invitation-only beta, so do what you have to to get your hands on it. It has a function built in which allows you to capture from your webcam (which is terrific if you have a shiny MacBook) which also works after you install macam/iChatUSBCam.
4. Start Photobooth: Photobooth is OSX’s built-in camera-grabbing application. It works just like those silly photo booths you find in malls – hit a button and in 3 seconds it snaps a picture. From what I have read, Photobooth doesn’t support USB cameras, and initially, I couldn’t get my camera going in Photobooth, but if I start Skitch first, then start Photobooth, then close Skitch, Photobooth magically starts working. I cannot explain why this is since it’s well outside my realm of knowledge (for now), but I know that it works.
Here are the (ridiculous) results:

Someday, when I am a famous Rock Star, this one is going to be my cd cover.

That’s right, I’m suspicious. Suspicious OF YOU.

And after my first cd, this will be the cover for my second cd. Creepy looking. I think it will be like a “Meg Unplugged” album where I wail depressing songs to an acoustic guitar. It’ll sell millions.
No, I absolutely have no plans on becoming an actual Rock Star someday, but it’s kind of fun to think about. I haven’t got a musical bone in my body.
…then again, neither do a lot of actual rock stars.