Using the cloud might be another option but I'm not a belieber in the concept that others can determine what they can do with my data.
The venerable Steve "Woz" Wozniak expressed similar trepidation, regarding the "cloud", urging all concerned to reconsider, for one, optical media held in environmentally secured storage. Tape -- the "real stuff" is a great option if you have access to a mainframe computer, situated safely in a salt mine or... I don't know. A hollowed-out mountain in Sweden? Arkansas?
Fine art photographers, and highly subsidized and staffed university, scientific, industrial and forensic photographers, might also consider "hard copy" in the form of printed proofs on archival stock, held in suitably secure storage. (Last year I saw a 150 year old photo produced in Paris'. Last night night I attempted to rescue files on a hard drive, produced last month.)
I do realize many NG members have tens, even hundreds, of thousands of images to store, making print-file solutions prohibitively expensive and/or impractically time consuming. For this, I have no definitive answer, save for rewording what was already said by others. The rest of us (artiste') retain relatively little of what we shoot; create artist's proofs, then run limited editions of prints offered for sale. (Sometimes the ruse works, and people actually buy our "art".) All else is in a book -- somewhere -- hopefully forever or until the world tires of us. (If you ever have trouble sleeping, I'll show you my portfolio. I guarantee you'll sleep for a month after that -- but don't blame me if you smash your camera against a rock later, or paint your walls black or something. I was even once told, a near-hysteric suffered psychosomatic blindness for weeks, mumbling something about never wanting to see another "cow, bug, tree or cute baby" again. But I think it was really just for days, not "weeks". You know how people inflate facts to drive a point home. Or, in my case, a spike into an eyeball.)
Just for the record: I'm not a fan of Apple™, nor a disenfranchised one time fellow traveler who fell out of favor with the cult of "Jobs". However, I have always respected "the Woz" for the engineer he was (still is) and if he says he smells smoke, I don't have to see flames to believe him.
