mwave offers the Western Digital 320GB My Passport Essential Portable 2.5″ USB 2.0 External Hard Drive in Charcoal, model no. WDBAAB3200ACH-NESN, for $39.99 with free shipping. That’s $0.12/GB, $5 under our May mention, and the lowest total price we could find by $10. This external hard drive runs at 5400 rpm and has a 2MB cache.