I recently got a second PowerBook and I created a second disk image file on my firewire server disk and placed a copy of SuperDuper on the new PowerBook so that I could do my wireless network backup.
When I was first getting SuperDuper running, I had trouble getting it to automount the network drive. I created this elaborate scheme where I would open a settings document on the PowerBook through an alias on the server (because I couldn't put the SuperDuper! settings document in the server because it is a package, and some of the filenames weren't compatible with the Windows box serving the disk).
But it turned out that none of that was needed. A properly configured and scheduled SuperDuper! backup will properly mount a network disk.
So all I really needed to do was configure the PowerBooks to wake up 1 minute before the scheduled backup.
Now, if I want to back up a PowerBook, I simply leave the lid up when I go to bed (a PowerBook will not wake up with the lid closed, unless it's connected to an external monitor). The backup just happens.
Simple and sweet.