If you were the type to think of 2.5″ drive technology only in terms of notebook products, then recently, Western Digital probably helped expand your horizons a bit.  With the release of their VelociRaptor 300GB SATA hard drive, mainstream users were exposed to the advantages of the high transfer rates associated with 2.5″ platters rotating at 10K RPM, with four access heads pulling data.  Though packed in a 3.5″ form-factor for desktop system compatibility, the 2.5″, dual 150GB platter platform that