My computer is about a thousand times faster than the one I first used in the 1970s. But it doesn’t feel particularly fast. I still spend time waiting for it to do things, especially start up or shut down or do anything involving a PDF file. The programs I use all day run at what seems a normal, not an astonishing, speed.

What does astonish me is how much data today’s computers can handle—which is where a lot of the new computing power has gone. They can create, transmit, format, and index extremely large files, and they can store practically anything. Every digital picture I have ever taken, every message or Web clip I might conceivably want to see again, every version of every document I have ever created—these all fit on my 100-gigabyte laptop hard drive, with room to spare. But the endlessly increasing data we see and store creates a risk of “loss” in two important forms.

Conceptually, the material you want can seem lost if you can’t find it amid all the unrelated files and messages. This is the problem that search engines help solve for the Internet, and that programs that sort and organize, like those described in previous columns (“The Electric Mind Meld,” July/August 2006; “Making Haystacks, Finding Needles,” November 2006), can offset on your own computer. Information can also be lost physically, through fire, theft, disk crash, whatever—and this is not even to mention the obsolescence of computers and formats themselves (see “File Not Found,” September 2006). For many people, the most damaging potential data loss would be their digital photos, since these proliferate so rapidly, are usually impossible to replace, and are so rarely printed out or preserved in other forms.

As long as people have used computers, they have been lectured to about the importance of making frequent backups to avoid the heartbreak of data loss. But the task has seemed so boring that non-geeks keep putting it off. Among the many nice features of the new backup systems I’m about to describe is that they make the process far more convenient and automatic than it has been before. Some even make it seem interesting.

In theory, every computer user should have a “backup portfolio,” with diversified holdings like those in an investment portfolio. At a minimum, copies of data should exist in different physical locations, so that a fire in your office doesn’t wipe out both your computer and the nearby stack of backup DVDs. That is the main weakness of the fastest and easiest form of storage, the stand-alone external hard drive—for instance, Western Digital’s My Book Pro, which costs about $300 for a 500-gigabyte capacity. Seagate, Sony, Buffalo Technology, and many other companies make similar, good systems for both Macs and PCs. The biggest size normally available is one terabyte, or more than 1,000 gigabytes. Such a drive is convenient because your computer sees it as just another hard drive (the D:\ drive, for instance, if you already have C:\), which in turn allows quick copying of your main drive’s contents onto the backup drive. External drives have become cheap enough to be a sensible standard investment for any user—for instance, as a repository for video or audio files, like movies or iTunes libraries, that take up a tremendous amount of space and could be replaced if lost. But for data you can’t afford to lose, they’re not enough.

Portable, lighter-weight external drives are a possible alternative, but have their own drawbacks. They’re about twice as expensive per unit of storage as non-portables (a 100-gigabyte portable drive from Seagate, for example, costs roughly $150). To my mind they’re a nuisance to carry around, and easy to lose or damage. I am much more enthusiastic about newly elegant approaches to protecting data, each involving the Internet, exemplified by the programs FolderShare and Mozy.

FolderShare, which runs on PCs and Macs, is a way to make sure you have backups of your most recent work available on all your computers. It was created by a small company in Austin that Microsoft acquired late in 2005. Microsoft has since incorporated FolderShare into its rapidly growing set of Windows Live Web-based services. (The extent of Windows Live offerings, current and planned, would surprise most people. See http://ideas.live.com and http://get.live.com.) Many Windows Live services have free basic versions and more advanced ones for a fee. The Folder­Share.com Web site says cryptically that the service is “now free.”