As I'm working, I frequently hit Ctrl + S to save my current document to the hard disk. Somewhat less frequently, I save a backup copy to a floppy disk, provided the file is small enough to fit on it (which it usually is). Somewhat less frequently, I save a copy through the Internet to an off-site backup disk. And still less frequently, I make a complete backup of all the documents on the hard drive of my primary work computer to a writable DVD disc.

I've never lost a document, despite making the not-so-uncommon, but no-less-brain-dead, mistakes of accidentally deleting an important file or destroying a current, nearly complete version of a file by overwriting it with a preliminary, incomplete version. I've also suffered one major data-destroying hard disk crash.

Another time I was a victim of a natural disaster. My wife and I were barbecuing when it started to rain, so we moved inside. I then heard thunder and nervously checked the computer in my office. I was working on a book and didn't want to lose anything. Everything checked out. Then….

Boom! The bomblike noise was accompanied by a small, momentary fireball on the ground maybe 100 feet from where we were sitting. Lightning had struck.

When I checked the computer again, it was dead. An enormous surge of electricity had blown right past my surge protector and fried the PC. But my data was still alive, saved by a backup.

Fortunately, I've never been victim to the kinds of horrendous natural disasters that have been all over the news in recent months. Hurricanes can destroy not only your computer, but also any backup hard disks, optical discs, tapes, Zip disks, Jazz disks, or floppies that you've dutifully made. This applies equally to tornadoes, fires, floods, earthquakes, volcanoes, landslides, avalanches, tidal waves, and meteor strikes. Despite the improbabilities, catastrophes do happen.

All this underscores the importance of off-site storage. These days, as a result of the Internet, saving important data off-site is easier than ever, with various options available.

One viable free option for home and small-office users is to save documents to the Web space that your Internet service provider offers, depending on how much space it gives you.

You can transfer files using the same tools you would use to upload files when creating a Web site. For instance, you could use a stand-alone file transfer protocol (FTP) program such as SmartFTP (http://www.smartftp.com) or the FTP tool built into another utility program such as VCOM PowerDesk Pro (http://www.v-com.com/product/PowerDesk_Pro_Home.html).

If you're going this route and backing up sensitive documents, you should encrypt the files to prevent Web surfers from perusing them (inadvertently or not). One easy way is to password protect these files using the popular Zip file compression format, which is built into many other utilities.

A more automated option is to use a specialized online backup service. A number of these services went belly up during the dot-com bust, but IBackup.com (http://www.ibackup.com) is still alive and kicking. For $14.95 per month, you have four gigabytes to play with.

Along with providing tools that you can use to schedule automatic backups of preselected data, IBackup also lets you make its remote-file server space look like another local hard disk, so you can manually drag and drop individual files to a safe, password-protected location. Unlike some other online backup services, you can use it to back up Mac and Linux files along with Windows files.

Xdrive (http://www.xdrive.com), which pioneered the concept of making remote file space look like local file space, is a similar service that also shows no signs of going away any time soon. Xdrive, which is available only for Windows, just upped its allocated space from 500 megabytes to five gigabytes per user, and it charges just $9.95 per month for the privilege. That's not enough to make a complete backup of most hard disks, but it's plenty for documents that most users create.

Like IBackup, Xdrive also provides other pricing options if you need additional storage for yourself or for multiple people. Along with using services such as these for remote backups, you can also use them for sending files that are too large for e-mail.

For more basic backup tips, check out the Web site Backup Critic (http://www.backupcritic.com).