The G4/Mini retrofit I was working on is now on hold. I took a rather nasty spill and smashed all the connecting tissue in my left wrist. It could be over eight weeks before it heals, or so the doctor says. I hope others will take heart and go forth with their own projects. On that front, I have some interesting news: ExpressHD is now offering the EFiX Dongle which allows you to run Snow Leopard on hardware readily available from most online computer stores. It is possible for us to retrofit our old Macs with third party gear to bring them into the new age. The EFiX Dongle sells for between 130 to 250 dollars depending on which model you buy. Here are some links to builds using the new technology. I've added the pros and cons views on it to let you make an informed decision.
I hope the information on these links will give you a better insight on this remarkable little device. I'm looking forward to getting back on track in the weeks to come and continue mt own build.