Hi everyone, I have a MDDM G4 with 80 gigs of hard drive. I have about 12 gigs left and would like to add another internal hard drive--probably 250 gigs or so, but I'm new to all of this so I would really appreciate any help anyone can offer. I have several questions listed below. 1) Is it possible to just add another internal hard drive instead of replacing the 80 gig that I have now? 2) What is all this talk about ATA? 3) Is there a specific brand/type I should buy? (I'm really unsure about this one because I don't want to wind up buying something that doesn't work for Macs, but does for Windows) 4) Will there be any compatibility issues? 5) Any recommendations on where I can get a good deal on one? Thanks!