If you put stock in a recent survey from Symantec, the company behind the Norton line of computer protection software, 57 percent of computer users who store personal data on their PC’s conscientiously back it up.

Those people can feel very good about themselves, because the same survey found that a quarter of computer users have lost computer data like documents, photos and music files, most commonly when the computer crashes.

For all those people who are feeling pretty good about themselves, here is something else to worry about: what happens to those beloved family photos or your extensive music collection if something should happen to your PC and your backup? A fire, flood or earthquake could destroy the backup sitting inches from the PC.

For years, big companies have been storing their backed-up data in multiple locations to protect it from disasters. The data of consumers also has value, and it is not always just an emotional value — like 99-cent iTunes music files, or videos downloaded at $10 a pop. It is not hard to accumulate a few hundred dollars’ worth of content that needs protection.

The recognition of the monetary value of data is one force driving the sales of external hard drives. The NPD Group, the market research firm based in Port Washington, N.Y., estimates that the market for external hard drives will grow 33 percent this year, to a $500 million category. That is largely because devices like the Western Digital My Book, Maxtor OneTouch or the Seagate Pushbutton Backup drives are easier to use and more stylish than past models.

Moreover, for about $150 you can get 160 gigabytes of storage, or about twice as much as you got for that price just three years ago.

Seagate, the leader of the hard-drive industry, is trying to solve the off-premises backup problem. It is pushing a device from its newly acquired Maxtor unit that allows consumers to back up data at home and off premises. The 500-gigabyte device, called Fusion, allows consumers to link the external drive to the home network so any computer on the network can grab content there.

Access is also possible from outside the home. The device comes with some elegant software created by Fabrik, a start-up company in San Mateo, Calif., that turns the hard drive into a personal version of Flickr or YouTube — you can invite others to view content. Some of the content on the drive can be designated public and the rest remains protected. The data can also be stored on Fabrik’s servers for 99 cents a month for one gigabyte of data and 49 cents for every gigabyte after that. One gigabyte is enough room to store 250,000 pages of text, 200 songs or about a thousand photos.

The network-attached storage category has not been as popular as regular hard drives, said Stephen Baker, vice president for industry analysis at NPD, because of privacy and trust issues. Consumers are wary about security once their data is stored or accessible remotely.

But the Maxtor Fusion may have other problems gaining acceptance. At about $700, it is nearly twice the price of other 500-gigabyte hard drives. Current Analysis, a San Diego market research firm, said consumers would pay only a $100 premium for this type of software and service.

The other problem comes after the box is taken home. The first part of setting up the storage device is a joy. Plug in the cables and turn it on. Run the software on the enclosed disc and within five minutes you can move data, photos, videos and music to the storage and to every device on your network. The second part, enabling the device to provide access to data from outside your home network is — well, let Maxtor’s user guide describe it: “This portion of the setup may prove challenging to complete.” Owners are faced with bewildering instructions about configuring the system to reroute dynamic D.N.S. addresses.

If you know what that means, then you won’t have a problem. For everyone else, be prepared to call Maxtor’s technical support to get it running. Better setup software could solve this problem.

(If you insist on knowing, computers seeking access to the home storage device from outside the home network have to know the address of the device. But because most Internet service providers do not assign a static address, an additional service has to be used to locate and route requests to whatever address your service provider has assigned to it.)

That said, the Fusion does what it promises. It is easy to store data and to designate what the public can see.

Mr. Baker predicts that the device will take some time to catch on. “It’s a next-year product,” he said. But David Tang, vice president for marketing at Fabrik, says it will appeal to the type of people using MySpace and to other creative types who want to share their content by streaming music or video to friends.

There are other solutions. Apple has been offering a backup service to Mac users who sign up for a .Mac account. It sells a one-year membership that entitles a user to one gigabyte of storage for $100. An additional three gigabytes costs $100 more.

There are several online backup services that work with the backup program on Microsoft’s XP operating system. For instance, Xdrive.com offers five gigabytes for $100 a year, and Backup.com offers the same amount for $500 a year.

It is worth shopping around for the best deal or considering a work-around. Google offers 2.7 gigabytes of storage space for anyone with a Gmail account. Although most people use it for archiving their e-mail messages, that is enough space to store 500 songs or 2,500 photos and a few spare Word files. You can do that by sending yourself an e-mail message with the files as attachments.

There’s an even easier way to take advantage of Google’s largess. Users of Internet Explorer can download a program called Gmail Drive. (A Google search for the term will point you to download sites.)

If you are using the Firefox browser, an even better downloadable add-on is Gspace. (You can find it at addons.mozilla.org/firefox/1593 or www.rjonna.com.) It puts a button on the toolbar of the browser that with a few clicks puts the file right into your Gmail account. Rahul Jonna, the Phoenix programmer who created it nine months ago, said the Gspace hack has been downloaded almost 500,000 times.

Its novelty may be limited. Google is considering a backup service called GDrive, and Microsoft says it will have a backup service called LiveDrive as part of its new operating system.

I.B.M. sees an opportunity in this consumer market for backup. It sells a consumer program named Tivoli that automates backup. Every time a file is changed, a copy is stored on the PC’s drive and a copy is sent to a backup device or a remote server. (That service is separate; you will not get to use I.B.M. servers.) The $35 program can be bought online only, in the “software downloads” sections of the Web sites of Circuit City, CompUSA, OfficeMax and Staples. I.B.M. is also selling the software to cable Internet providers, like Comcast, which will offer its customers automated backup to their servers.

Symantec, when it was done surveying the backup habits of users, decided it needed to jump in, too. Its new PC protection program for consumers, Norton 360, available in March, will include a function for backing up data online.