well this is just a small part of a large mod (complete case from scratch) im making. By hotswappable, i mean being able to take out harddrives without turning off the computer. I do this ALOT (changing harddrives) and this would really help. The reason i mentioned external enclosures is that when your done with using a portable hd, you just turn off the enclosure and disconnect it. Thats what im wanthign to do, just build into the case. I could go out and buy 5 esata enclosures and just take off the hardware and not use the cases, but that would be very expensive.