If you lost your cell phone right now, how many people would you be able to call? What about your PDA, or computer? If all the magic smoke came out, how long will it take you to be up and running?
Hopefully, all data that cannot be reproduced, such as your priceless photos and home movies, will have a secure backup of your prefered manner. What about the data that is easily gotten but has taken years to accumulate? Often times this will fly right under the radar.
Then again, it's not possible, at least not yet, to backup any and every piece of information. Appropriate selection is necessary.
Whatever you decide don't be the one to ask the question: "Backup, what backup?"