what does this camera look like? and what does this mac look like?The PowerMac G5 never came with a camera of any kind. Its possible that you have an external iSight, in which case it can be used to video chat using Skype, iChat, and a handful other other applications.
It will not work with MSN as Microsoft doesn't support video chatting on the Mac yet. There are some third-party applications that allow limited video chatting functionality over the MSN network.
Its also possible you have an iMac G5 with an internal iSight, in which case the answer is the same.
There's a chance you have a third-party external webcam, which you may or may not be able to use in programs like Skype/iChat.
The last revision did. [EDIT: I misread your post, he said it was a PowerPC, not PowerMac, so I would guess he does in fact mean the iMac G5]The PowerMac G5 never came with a camera of any kind.