A different, intriguing approach is a program that backs itself up online. Intuit, for one, offers a service that preserves your Quicken financial data on professionally managed servers. It's cheap—only $10 a year—and will even back up data from another Intuit program, Home Inventory Manager, which catalogs home possessions.
Broader systems like MediaMax are great. But they take planning, forethought, and some discipline. The Quicken system is more foolproof, asking to copy its files each time the program shuts down. I've seen some hiccups; Quicken sometimes can't connect to the backup service. But it's targeted and provides its own discipline.
Maybe a similar Apple service could back up the music I've stored in iTunes. But it would probably be costly, judging from a service that Adobe offers for photos, which would cost me hundreds of dollars a year.
And it would be confusing with a collection of backup accounts to sift through after disaster. But until Microsoft makes Windows smart enough to automatically find and back up all my crucial data, more programs should offer to protect themselves.