I will suggest you to buy a Seagate FreeAgent Go Portable Hard Drive of 1TB. Dimensions: 5.12" x 3.15" x 0.49",
Weight: 5.64 oz.,
Capacities: 1TB,
Drive type: 2.5" 5400-rpm drive,
Power source: Bus-powered,
Software bundle: Seagate Manager,
Warranty: Five years