I have written several times about the need for making backup files. Probably the safest method of making backing files is to use one of the online file storage services. Not only do these services provide backup copies, they also store them off-site. Off-site storage can be a critical factor when it comes to storing your most important information. Just ask anyone who lost a home in Hurricane Katrina, in one of the western forest fires, or in a tornado. Everyone should have their genealogy data as well as their old family photographs, checkbook data, income tax information, email messages, and many other items stored in a distant digital repository for safekeeping.
My current favorite backup service for Windows XP users is Mozy at www.Mozy.com. For Macintosh systems, I'd suggest BackJack at www.backjack.com. In times past, I have also written about Xdrive, IBackup, and others. Now Listable.com has a list of 171 (count 'em!) online file storage services, and that number is growing. It may be more than 171 by the time you read these words. I suspect you can find a suitable backup service somewhere in that list!
To be sure, the list of online file storage services at Listable.com does not contain full reviews of each service. It is simply a list with a one- or two-sentence description of each. It lists free and for-pay services alike, as well as those for Macintosh and Windows and those that serve all operating systems.
You can find the extensive list of online file storage services at http://www.listible.com/list/online-file-storage.
Now, go back up your most important files, OK?