Using Pictbridge port as USB port (canon printer)

Hello, I have a question concerning Pictbridge. I'd like to use my Canon Pixma iP4300's Pictbridge port as a USB port so I can connect my camera and transfer photos to my mac. I am all out of USB ports, so this would make this way more convenient. The pictbridge port on the printer works, but my mac doesn't detect what is connected to it. Is there a way to get mac os x to detect that pictbridge port?
thanks