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A not-so funny thing happened on the way to writing this column. The power on my street zapped out for a few seconds after what sounded like a transformer in the neighborhood blew.

Good thing I'd saved the file to my computer before the screen went blank. But what if I hadn't, or hadn't set up my writing program to copy unsaved drafts in the event of unexpected shut downs? Even worse, what if the power went off -- and stayed off -- because of a storm, tornado or hurricane?

That, my friends, is why backing up computer files is a good idea.

Whether you prefer a cloud-based service or an external hard drive, there have never been more inexpensive alternatives for saving or backing up data.

Here are several options:

Google Drive - Launched in April 2012, Google Drive is Google's online file storage and sharing service. You can use it to save Google Docs, Gmail and other types of files online, or work within them in real time with other people. Download the program and it creates a folder on your computer that syncs with the Drive website as well as a Drive mobile app for Android or Apple iOS devices. After that, you can work on a file from anywhere and updates are saved to Drive and all your devices. In the past year, Google bumped the amount of file storage available on free personal Drive accounts from 5 gigabytes to 15 GB. Paid accounts range from $4.99 a month for 100 GB to $99.99 a month for 2 terabytes. Drive also stores notes, drawings and documents created in other Google apps; see a list of all Google Drive apps in the Chrome web store.

SkyDrive - If you're a heavy Microsoft Office user, you might prefer SkyDrive, the latest iteration of Microsoft's cloud-based file storage and sharing service (Disclosure: Microsoft owns MSN Money). Like Google Drive, SkyDrive consists of a downloadable program, website and mobile app (for Windows Phone, Android and iOS devices) that can be set up to sync files, photos, music and videos from a desktop, laptop, smartphone or someone else's computer. SkyDrive users save more photos than any other file types, according to Microsoft, which could explain why in May it rolled out improved photo upload and timeline features. SkyDrive also incorporates Outlook.com email, calendar and contact manager. Free personal SkyDrive accounts include up to 7 GB of file storage (or through December 31, 10 GB for college students with an ".edu" email address). Other accounts range from $10 a year for 27 GB to $50 a year for 107 GB.

MozyHome - As cloud-based file storage go, Mozy is the old timer, selling secure online back-up services to businesses and individuals since 2005. The company's MozyHome personal backup plans include a file sync feature called Stash that updates commonly used files across multiple computers and mobile devices. A free, entry-level MozyHome account includes Stash and 2 GB of file storage. Otherwise, the service is $5.99 a month for Stash plus file storage of up to 50 GB on one computer, or $9.99 a month for up to 125 GB on as many as three computers.

Amazon Cloud Drive - If you've ever bought a book, movie or tube of toothpaste on Amazon, you've already got a free Amazon Cloud Drive account, good for storing up to 5 GB of documents, e-books, videos and other files. You can use Cloud Drive alone to upload and save individual documents of up to 2 GB, or download the Cloud Drive desktop app to organize files into folders. Additional file storage is available at prices ranging from $10 a year for 20 GB to $500 a year for about a terabyte. In May, Amazon introduced a Cloud Drive Photos app for Android and iOS smartphones for uploading, saving, viewing and sharing photos.

Dropbox - Dropbox is a cloud-based file transfer and sharing service, but you can use it to back up data too. The service, which according to one report has more than 100 million users, includes mobile apps for Android, iOS, BlackBerry and Kindle Fire devices. Dropbox offers a free personal account of up to 2 GB, but you can earn 500 MB in addition to free storage space for every friend you refer to the service, up to 18 GB. Pro accounts start at $9.99 a month for 100 GB. In March, Dropbox bought email startup Mailbox and plans to integrate email attachments and other features into its products. A similar, competing option is Box.net, which offers free personal accounts for storing up to 5 GB of data, including video or presentation files of up to 1 GB each.

External hard drives - Another option for backing up or storing files is an external hard drive. Newer models are the size of an e-book reader or smaller, can store up to 2 TB, and cost $75 to $200 depending on a particular unit's storage capacity. Many work on wireless or wired networks or both, come in snazzy colors, and are sold online and through big-box electronics resellers. PC Magazine gave its Editor's Choice endorsement to the Seagate Wireless Plus, a 1 TB hard drive that retails for around $200. The device has a built-in Wifi router so you can stream photos, video, music files or e-books to a smartphone or laptop even when there's no Internet connection around. CNET gives an "Excellent" rating to Western Digital's WD My Passport Ultra, a 2.5-inch drive that comes in four colors, measures 4.3" by 3.5" and hooks up to a laptop through a USB port. The 500 GB model retails for about $100, and the 1 TB version for $130.

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The point isn't that one method is better than the other. It's that you choose something to back yourself up. When disaster strikes, or your computing device of choice experiences a data-vaporizing event, you'll be glad you did.

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