I just set up Time Machine to backup to a network drive.  It was surprisingly easy to do.  As simple as creating a disk image in disk utility and telling time machine where to find it.  I followed this tutorial.

The part that got me was naming the image.  I missed that part and didn’t put my MAC address as the name:  ComputerName_MACAddress.sparesebundle

Now I just have to get ghost to do the same thing for my Vista machine.