Portable Hard Drives

Portable drives can be powered through your computer

Portable external hard drives come in smaller capacities than desktop models and are powered through the USB port. This makes them a good choice for laptop users or anyone who needs more portable storage.

Experts recommend the portable Seagate FreeAgent Go more often than any other external hard drive, portable or not. This drive has been on the market for a few years, and owners say it has proven reliable; very few complain of drive failure. It also offers a lot of storage for the price, in 250 GB (*Est. $70 for 250 GB), 320 GB (*Est. $80), 500 GB (*Est. $105) and 640 GB (*Est. $120) versions. At less than 6 ounces, the palm-sized drive is small and light, and Seagate backs the FreeAgent Go with a five-year limited warranty.

The FreeAgent Go is powered by the connected computer through a USB 2.0 port (cable included). The included backup software is Windows-only. Separate Mac versions are available: the USB-only Seagate FreeAgent Go for Mac (*Est. $95 for 250 GB) and the 500 GB Seagate FreeAgent Go Pro for Mac (*Est. $140), which adds FireWire 400 and 800 ports and cables. The Mac versions don't include backup software, but they're compatible with the Time Machine backup software that comes with Macs. A desktop dock costs $30 extra with the USB versions, but it's included with the FreeAgent Go Pro for Mac, and reviews say it's nice to just slip the disk into its dock and skip fiddling with cords.

A few runner-up portable hard drives get great ratings, but none is recommended as often as the Seagate -- and they all cost more per gigabyte.

The Iomega eGo (*Est. $80 for 250 GB) offers separate PC and Mac versions, like the Seagate. The PC version is USB-only, but the Iomega eGo Mac Edition (*Est. $90 for 250 GB) also has FireWire 800 and 400 ports. PCMag.com and CNET like the Mac version, especially if you're running an older Mac: The eGo is compatible with Mac OS X 10.1 and later (the Seagate FreeAgent Go starts at OS X 10.4.9).

If you're looking for the easiest possible backup method, PCMag.com and The Wall Street Journal say the Clickfree (*Est. $95 for 250 GB) portable USB drive is the simplest you can buy. It backs up your key files every time you plug it in -- you don't have to do a thing. It works fine with both PCs and Macs in The Wall Street Journal's test, although another expert source says you can't alternate between the two (without reformatting the drive and erasing the data). The Clickfree gets outstanding reviews from owners at Amazon.com.

Western Digital offers a few lines of its My Passport portable drive, but experts and owners like the top-of-the-line Western Digital My Passport Elite (*Est. $100 for 250 GB) best. Like the Clickfree, the My Passport Elite performs an automatic backup every time you plug its USB cable into your computer, and it's compatible with Windows and Macs. Experts appreciate its advanced features (such as a capacity gauge that tells you at a glance how much space you have left on your drive) and its five-year warranty. The My Passport Elite gets excellent reviews from owners at Amazon.com and Newegg.com, although several say the included Windows-only backup software isn't great.