Mull those options over. If you're looking for off-site backup, storing valuable data files on another computer at the same location may be effective, but it hardly defines the "off-site" concept or protects you from catastrophe. Your friend's computer, remote as it might be, is an interesting possibility. Your data is encrypted to prevent unwanted intrusion, but you should assure yourself that the friend in question isn't a glazed-eyed slacker with an overclocked PC that crashes every half hour. The idea of backing up your data is to keep it secure and retrievable.

While the CrashPlan backup severs might now seem the best option, it too has its caveats. It will cost you $5 per month for 50GB of data and $0.10 for every gigabyte over that amount. Let's say you don't have a problem with the fee. According to the CrashPlan FAQ, it can take as long as 20 days to backup that 50GB and three or four days to get it back. That's not a limitation of the base software. The upscale edition simply adds real-time backup (as your data changes) to the mix rather than just scheduled or manually initiated backups. Instead, it's a matter of available transmission speeds and priorities.

Cutting through the underbrush, CrashPlan does work in its own mysterious ways. You have complete freedom in selecting the data sets you want backed up, as well as choosing the destination for that data. Retrieval is just as straightforward. The only fault we found is that it doesn't seem to have a simple way to cancel a backup once it's begun. On the other hand, if for any reason CrashPlan can't connect to your destination, you'll receive an e-mail notification that there's a problem. Ours arrived after six days of attempts.

Should you rush out and get CrashPlan? We'd probably vote no if we were talking it seriously. This appears to be a "Web 2.0," touchy feely, "friends back up friends" concept. ("It's surprising how many people want to be your friend when you're their backup destination," quote the FAQ.) You know your friends. Would you feel secure if they had your data?

Right now, the better option for a desktop PC's off-site data security still appears to be something on the order of an Iomega Rev 70 cartridge hard drive system or, more simply, a CD/DVD backup regimen. You can then take the media down to your own bank and store it in your own safe deposit box on your own timetable. It's not as sexy, but it's probably more reliable in the long run.