I was interested in this too, but most of the tutorials for the slim you would have to be willing to give up the UMD bay. For phat, you can place the camera internally on the opposite side of the battery. In both case you would have to be comfortable with soldering and cutting because you would have to install a switch to go back and forth from USB to camera since they share the same connection.
Another interesting thing for people to look into is putting to use the cameras on our old phones and/or laptops. If we could just get more detailed information about the workings of the cameras and connection points on the psp boards, it might be possible to put an internal camera into the slim without loosing the UMD drive.
