Dang this post is old-skool. Rather then mulling over the pros and cons of mounting your hard drive, just to sum it all up, there is not conclusive results as to mounting your HD horizontally or vertically. The only theory that exists that mounting your HD horizontally MAY introduce vibrations which can cause the internal plates within the drive to move, getting scratches from the read/write heads in the process. I can attest to this being a possibility because I had a non-flash based MP3 player crap out on me when I used to take it running a couple years ago. That was when they first came out and I just had Creative replace it. But my vertically mounted hard drive has never suffered any skips or problems. Mount horizontally if that is what works best for you. But most seem to prefer verticle. But again, nothing concrete says either way is best.
