Hey, So I am planning on getting an External HDD for use with Time Machine as well as general storage and need some help deciding what to get. Some questions I have are: 1-I have a 500GB harddrive in my iMac. Should I get at least that in a backup? 2-What sort of interface should I get, USB, firewire 400 or firewire 800? Is firewire faster than USB? 3-What other factors should I consider when getting an HDD? 4-Any good suggestions? Thanks, I appreciate it.