So now I'm following Lee Joramo's instructions for installing Snow Leopard on the Mac Mini, in target mode. So far I've got the Mini showing up as an external hard drive on the MacBook.
Update: It worked. I got a clean installation of Snow Leopard on the Mac Mini, using the method outlined by Lee. Unfortunately it didn't get the scanner working. I give up on that. I'll try getting another scanner. Canon LiDE 700F is a bad deal. I hear the hardware works, but the drivers are a nightmare. I concur with the drivers part, never got to use the hardware.
Update #2: Netbook haters are going to scream when they hear this. The Canon scanner works great on Windows XP on my little Asus netbook. The cool thing is that Windows has this built-in function that gets the drivers for you. I have no idea where they go or how it works, but -- it worked. I was able to scan all my tax forms, about 100 pages, in about an hour. I did it using the built-in Windows scanning software. No I did not do this just to irritate Mac zealots, but I'm kind of pleased that it probably will. ">