I just changed out the 320 GB HDD I had my MBP and upgraded to the 500 GB Momentus XT hybrid. Should I try and get a few bucks back from the old HDD or keep it? I am thinking maybe keep it because I lost my snow leopard install disk and I can keep the old HDD as a back up if this one ever dies. I could just swap out the drives, the old HDD already has Lion installed - then just run my restore to get my files all up to date from the latest backup on Time Machine, then I could just clone it again to a new drive. I'm thinking the old drive is probably not worth much anyway??