John Gruber writes about his recent hard disk crash:
Hard drives are fragile. Read as much as you can bear to about how they work, how incredibly precisely they must operate in order to cram so many bits onto such small disks. It’s a miracle to me that they work at all. Every hard drive in the world will eventually fail. Assume that yours are all on the cusp of failure at all times. It’s good to be spooked about how long your hard drives will last.
Luckily he had good backups, which saved his butt.
Merlin Mann gives more hints on smart backup strategies:
Perform automated, redundant, and rotated backups as often as you can afford to lose every single bit of information that’s been changed or added since your last backup. Because it’s going to go away.
This is exactly why I prefer CrashPlan instead of Time Machine. CrashPlan will automatically backup to multiple destinations, which can include both a local drive and CrashPlan Central, which provides off-site backups for extra security. Unlike Time Machine, which doesn’t work well on network drives other than a Time Capsule, CrashPlan is perfectly happy backing up over the network, which is a big plus for laptops.
CrashPlan is only one part of my backup strategy. Although I use it to back up my MacBook continuously, I use Time Machine on my iMac with a FireWire drive since it stays on my desk. I also use DropBox to sync most of my critical folders between my iMac and MacBook. I also do regular full drive backups with SuperDuper.