What if you're not lucky enough to get to the photo albums? Maybe you've digitized your old pictures and backed them up on discs or an external hard drive. But that does no good if natural disaster hits, and you can't get to them in time. And what about the rest of your digital life — music, videos and the like?

Tech-savvy consumers are looking to online backup services for peace of mind. For years, these services were either unreliable, hard to use or very expensive — but that's changed.

Two companies, Mozy and Carbonite, now offer unlimited storage for about $50 yearly, or about half the cost of a 500-gigabyte hard drive.

"The beauty of online backup is it is off-site," says Vance Checketts, a director at Mozy in American Fork, Utah. "It's not on a DVD or hard drive in your living room that may go up in flames or die on you." Mozy has 350,000 subscribers, up from 100,000 in early 2006, Checketts says. Rival Carbonite says it has more than 100,000 subscribers.

A 500-GB hard drive can hold 8,000 hours of digital music, 160,000 photos, 500 hours of video or 250 games, says hard-drive manufacturer Seagate. The idea of amassing even more digital content may sound far-fetched, but most PCs now come with at least 250 to 300 GB to accommodate space-hogging digital photo and music libraries, videos and documents.

Hard drives are the primary vehicle consumers and businesses use for backup. About 495 million drives were sold in 2006, according to measurement firm IDC, worth $30 billion. Seagate dominates the industry with 35% market share.

Another backup choice is saving media to CDs or data DVDs. But as digital photo resolution increases, so do file sizes. It is getting tougher to back up to a CD that holds a puny 700 megabytes, or 200 to 300 photos. Even a DVD, at 4.7 GB, won't hold big movie files.

New high-definition DVDs offer higher capacities, but they're pricey — about $500 for a burner, and $10 a disc, compared to about 25 cents for a regular DVD.

To back up to online, most services ask you to download a small piece of software, which resides on your computer and acts as a virtual drive. The programs can be set up for automatic backups, or you can drag and drop individual files.

Delivery depends on your connection speed and how much data you are sending. Video files tend to be the largest type of data. Checketts says that backing up video can take "hours, days or even a week."

USA TODAY began testing backup with Mozy on Monday afternoon, transferring 75 GB of material. By mid-Tuesday, just over 10% had been uploaded.

Justin Inda, a video editor for Wild Eyes Productions, which produces documentaries for the History Channel, knows well about losing data. He's lost six hard drives in five years, including video projects and his entire iTunes music collection.

His hard-drive failures came from power surges, which fried the data.

"I now back up everything on at least three drives per day," Inda says. "Drives are cheap enough for people to pick up extras, back up everything and ship it to a relative's or friend's house for safekeeping." He sent an extra copy of his video-editing demo reel to his parents' home in Florida.

"I've learned my lesson the hard way," he says.