(At least during installation: if not allowed, then the list for 'Canon IJ Network' in the Network Setup program will be empty. (My printer cd is labeled PIXMA iP4000R Setup Software & User's Guide, MCD 1.1, QH7-1581, copyright 2004.)
Especially for those installing a wireless printer but facing an empty list for 'Canon IJ Network', here's what I've written down after installation of a PIXMA iP4000R on 10.5 Leopard, a long time ago: Not 10.6 specific, but just for the archives.