Seagate Slim: The 9mm-thin Seagate Slim is appropriately named. It leaves the factory with a USB 3.0 interface, but since its based on the Universal Storage Module standard, you can purchase an optional Thunderbolt interface for $100 (youll need to provide your own cable). It comes formatted for NTSF, but Seagate provides an NTFS driver for the Mac. On the downside, this model delivers only 500GB of capacity.
Click here for our hands-on review of the Slim in a PC environment.
Western Digital My Passport: For people who need a lot of storage on the go, this drive packs up to 2TB of space into a package that weighs just 8 ounces. It comes with a USB 3.0 interface and a collection of utilitiesincluding automatic back-up softwarefor both the Mac and the PC.
Click here for our complete review of the My Passport in a PC environment.