When will you actually use a 7mm-thick HDD? You hardly or probably won’t even be using these low profile hard disks. Hitachi has increased their 7-inch single-platter’s density to swallow 500GB worth of data for you. This single-platter archivist measure 2.5 inches diagonally, but as its Z5K500 product name suggests it only spins at the ‘tame’ rate of 5400RPM. The less generously proportioned Z7K320 offers 7200RPM if you’re after more oomph, but the price will probably swallow you up. I won’t be surprised if you can’t get this yourself and your first contact with ‘em will probably be in the form of any ultrathin netbook/notebook.