I can still remember a time when I got a computer with a 4.3GB hard drive and thought to myself, "I'll never fill that!" Times change, things get bigger, and before you know it, you're out of space. Heck, a basic install of virtually any modern PC game takes up more space than that entire drive. PC pack rats like myself will run short on space even faster, and with more and more sensitive personal information going digital each day, so grows the importance of backing up that important data on a drive NOT inside your computer should it have a serious problem. Data portability is also becoming a necessity. All of these issues can be solved by Western Digital's MyBook series of external hard drives.
They come in a range of sizes, from 80GB all the way up to about 1TB, and they're still growing. I can say about 1TB what I said about that 4.3GB a few years ago, but I'm sure that'll change. You also get a bevy of interface options, including USB 2.0, SATA/300, and FireWire, depending on the model you choose. They all spin at 7200RPMs, giving you solid speed performance without needing their own cooling fan or anything.
For once, plug-and-play lives up to its name. Plugging it into your Windows PC or Mac, you'll likely have to format it first, but from there it's yours to do with as you please. The reviews of it at Newegg.com are mixed, some stating even that it can't be formatted to NTFS, which is simply not true. They also complain of the drive failing entirely after a short time, but I've had mine for over a year and haven't had a problem with it yet, despite using almost the full capacity of the drive.
I've tested out the older version (with the green LED ring on/off button on the front) and the newer model (with the alternating blue LEDs on the front) and the only mechanical or cosmetic defect in either was that the book-shaped enclosure of the newer design started to slide open once when picking it up. I suppose if you grabbed it in a hurry or were swinging it around like an idiot, it would come all the way off and you might have a problem, though rough handling of a drive is just asking for trouble. That said, there are also fair arguments about the warranty on these drives only lasting one year, whereas Seagate and Maxtor offer five-year warranties on similar (and more expensive) products.