The Momentus Thin – that’s the new, ‘super thin’ laptop and netbook hard drive announced on Monday by Seagate Technology. At barely 9.5mm, the regular 2.5-inch laptop hard drive, Momentus Thin is almost 25 percent thinner than the conventional 25.4mm hard drives of 3.5-inch desktops.

Boasting performance akin to a regular SATA 2.5-inch hard drive, which is faster than most of the low-end SSDs used in netbooks, the Momentus Thin will be available in two capacities - 250GB and 160GB. While the larger, 250GB, version will cost $55, the price of the 160GB version has not been revealed by the company.

Scheduled for shipment to Seagate’s resellers in January, the Momentus Thin features 8MB of cache memory, supports a SATA 3Gbps interface, and rolls at 5400rpm. It also offers the regular Seagate Momentus drives’ features like self-encryption, FIPS 140-2 certification and free-fall sensors for shock tolerance.

Since the Momentus Thin will be capable of fitting in any application that requires a 9.5mm hard drive, it will facilitate the users in upgrading their existing storage by themselves.

About its new Momentus Thin drive, which will also evidently target backup devices and other consumer electronics, Seagate said in a statement: “The Momentus Thin drive provides the lowest- cost storage for netbooks and thin laptops, enabling computer makers to offer systems that reach a broader market.”