With the proliferation of malware, spyware, and computer viruses ready to do their worst to your system, data is more important than ever. But between your huge media files and multitudinous text documents, you're going to want a backup device that can handle the load. With the Seagate ST9160821U2-RK External 160GB hard drive ($290 street), that shouldn't be a problem. The ST9160821U2-RK is a notebook-class external hard drive with the largest capacity of any portable hard drive currently on the market. It uses perpendicular recording technology to stuff 160GB in a physical space that used to top out at 80 to 100GB. This means that you'll definitely have the space to backup your entire notebook, or even many of today's desktops. Alternatively, you can save thousands of MP3s, digital photos, and hours and hours of video from your digital life. The drive also bundles in Mac OS X-compatible software, and features a well-thought-out dual-head USB cable. But such capacity in a portable drive comes at a high price, not to mention more weight.

Perpendicular technology is an important innovation in data storage and, to some extent, turns file backup on its head or, er, side. Think of how you stack books on a shelf. You can fit more books on the shelf if you place them upright side by side rather than lay them flat in a single layer. Likewise, the bits on a perpendicular drive are stacked vertically rather than horizontally as they have been in the past. That method, plus an extra drive head and new platter material, lets Seagate and other manufacturers squeeze more data onto drives of the same size.

The Seagate drive comes in a protective metal case with cooling vents milled in its side. At 0.75 pound, it's a little heavier than other drives in its class, which usually top out at half a pound. The ST9160821U2-RK comes with a good dual-headed USB cable, with each plug able to reach either end of a large notebook, like the Apple PowerBook G4 15-inch and Toshiba's Satellite R25-S3509 convertible tablet PC. This is important, since some notebooks (and desktops) have low-powered USB ports: If there isn't enough juice to power the drive, it's unusable. (Some USB ports put out enough juice to power everything, but some put out only enough to power flash drives and peripherals like mice and keyboards.) Thankfully, many new notebooks have high-powered USB ports, but it's still imperative to have the option of being able to use two USB ports to power the hard drive if you use older PCs.