The Samsung 500GB S2 is an external hard drive featuring Samsung Auto Backup and SecretZone.
Source: SlashGear
The Buffalo Dualie is a combination hard drive and iPod/iPhone dock. It comes bundled with a 500GB HDD.
Source: Engadget
The Western Digital My Book 3.0 features 1TB or 2TB storage and USB 3.0 interface.
Source: Engadget
The LaCie 2Big USB 3.0 is a dual drive RAID 0/1 system with USB 3.0 connection for read speeds up to 275MB/s.
Source: HotHardware
The LaCie Rikiki is the world’s smallest 2.5-inch external hard drive available in 250GB, 500GB and 640GB capacities.
Source: HotHardware
The OWC Mercury Elite-AL Pro Mini is a portable hard drive with eSATA, USB 2.0, and Firewire 800 connections. Capacities range from 320GB to 500GB and an SSD option at 256GB.
Source: HotHardware
The Drobo S features 5 bays, dual-drive redundancy and eSATA connectivity. It also sports a faster processor compared to the standard Drobo model.
Source: HotHardware
The Samsung STORY Station Plus features a 3.5-inch 2TB drive with eSATA connectivity.
Source: Gadget.com
The Hitachi SimpleTech Duo Pro supports dual HDDs for up to 4TB of drive space. The drive supports RAID 0/1 and connectivity via eSATA and USB 2.0.
Source: SlashGear
The Hitachi 2TB SimpleTech SimpleDrive features a 2TB Hitachi Deskstar 7K2000 drive internally and USB 2.0, FireWire 400, FireWire 800, and 3Gb/sec eSATA connetions.
Source: Electronista