One of the rules of real estate is that when you can’t build out, you build up. The same thing applies to hard drive platters. Writing a longer, tighter data spiral on a platter will increase the capacity of the drive, but eventually you’ll hit some unforgiving physical storage limits.

Perpendicular storage was developed with some foresight to overcome this problem. By standing bits vertically instead of writing them all horizontally, capacity and transfer speeds increase while the drive remains the same physical size. It’s responsible for the fearsome Seagate 750GB desktop drive, but there’s no reason why the technology can’t be applied to other drives.

Western Digital has put this technology into its new line of hard drives for notebooks. The drives are available in EIDE or SATA versions, and come with a three year warranty. The 160 GB 5400 RPM drive should set you back about $339. It joins Toshiba and Fujitsu’s offerings in the world of perpendicular recording.

If you don’t have a laptop, just think of some hacks and other potential uses for a drive like this. Using a laptop drive saves power, noise and space. Exactly the things you’re looking at saving in a media centre. External cases for laptop hard drives can now be filled with more information in the same space.

If you think even smaller, and put perpendicular storage into smaller form factor hard drives, like the 1.8” drives that power MP3 players, the result is larger capacity players in the same size we are used to.