I want to get a second computer to run iTunes and web apps alongside my 12" PB. My original intent was to get a Mini and an external drive or two, but I've found a good deal on a G4 tower that may prove to be worth the space hassle compared to the mini. What I'd like to know though, is if it would be possible to use the powermac instead of the external drives? If I filled the PM drive slots with what I had planned to be external drives, can I then hook up my PB to the powermac somehow to back up my data, etc? Will the slower speed of the powermac (450mhz) cause issues?