OK, so I have an aluminum iMac 20", 4GB RAM, OS X 10.5.5. Am I correct in assuming that there is software out there, hopefully free, that I can use to run Tiger or some older "classic" OS? An emulator for System 7 would be really cool. This is just for nostalgic value, as I used a System 7 Mac in the first grade computer lab. Tiger seems more complicated, but then again I am new at this. Anyone?