WD Caviar 640GB High-Performance Black Edition SATA Drive for $73.99 Shipped

Western Digital Caviar 640GB Black Edition SATA Drive with 32MB Cache for $73.99 shipped.  The Black Edition has a 5-year warranty and is Western Digital’s high-performance product line of SATA drives that usually require a premium.  More information can be found here.  Note that it comes in OEM packaging, which means no pretty retail box and marketing materials but is otherwise identical.  Others usually sell it for about $85.