No one likes to think about disasters such as burglary, earthquake, fire, the zombie apocalypse, or other catastrophes that could potentially wipe out your Mac, your other gadgets, and perhaps even your entire home or office. But these things do happen (with the possible exception of the zombies), and despite your best efforts, you might not be able to prevent the loss. You can, however, minimize the damage and inconvenience you'll suffer--and speed your recovery--by making sure you've taken a number of commonsense steps to prepare for misfortune ahead of time.
Insurance
Let's start with your hardware itself--your Mac(s), hard drives, monitors, printer, scanner, and so on. If you pulled into your driveway and found a huge crater where your home used to be, replacing that equipment will probably be in the top ten items on your post-tragedy to-do list. Will your insurance cover it? If you haven't checked into that question specifically, this might be a good time to study your policy or chat about it with your insurance agent.
I've found that homeowner's and renter's policies vary greatly with regard to their coverage of computer equipment, especially laptops. Some of them cover computers only when they're in your home, only up to a predetermined limit that's much lower than your overall policy, or only if the equipment is personal property and not business property. You may be able to purchase a rider that adds (or increases) coverage for your computer equipment. Alternatively, you can buy a separate policy that covers only personal property in general (such as State Farm's Personal Article Policy) or computer equipment in particular (such as Safeware's insurance policies).
Backups
Once your insurance settlement has come through and you've purchased a new Mac, you'll want to restore all the data that you wisely backed up and stored offsite. Um... you did back up all your data and store a copy offsite, didn't you? If not, now's the time to start doing so--right now. Local backups (using Time Machine with an external hard drive, say) are great for quickly restoring files that go missing in the normal course of events. But if your house burns down with those external drives inside, you'll be out of luck if they were your only backups.
There are two main ways to get offsite backups. First, you can use a cloud-backup service such as Backblaze, CrashPlan, or DollyDrive to store a copy of your data in one of their remote, secure data centers. When it comes time to restore that data, you can either download it (which may take quite a while if you're restoring tens or hundreds of gigabytes) or request that your data be sent to you on an external hard drive (for an additional fee, of course). Cloud-backup services won't be able to restore your operating system and applications, however.
An alternative approach, which does let you store a complete copy of your disk offsite, is to make a full backup on an external drive, then store that drive at the home of a friend or relative, at the office, or in a safe deposit box. That's not a bad idea, but it's more work than a cloud service--especially if you want to keep that backup up to date (which you do).
In case of theft
If a thief absconds with your Mac, you may still have to deal with insurance and backups, but now you have an additional problem: The thief has access to your data. You certainly don't want a criminal browsing your contacts, looking at your photos, reviewing your bank records, and so on. There are some things you can do thief-proof your Mac:
FileVault The best way to prevent unauthorized access to a stolen Mac is to encrypt its contents with FileVault. It's easy to set up, has a minimal impact on your Mac's performance, and makes your data nearly impenetrable by anyone who doesn't know your login password. (You are using a strong, unguessable login password, right?)
To set up FileVault, go to the Security & Privacy pane of System Preferences. Click the lock icon, enter your administrator username and password, and click OK to unlock it. Then click the FileVault tab and click Turn On FileVault. You'll be prompted to follow several additional steps, one of which is writing down a recovery key that you can use to access your data if you should forget your password. Restart your Mac to begin the encryption process. Your Mac will be a bit slower for several hours or more until the process completes, but you can continue using it in the meantime.
Find My Mac If you want to give the police a better shot at recovering your stolen Mac, make sure you've enabled Find My Mac on the iCloud pane of System Preferences. (That, in turn, requires that Location Services to be turned on, on the Privacy tab of the Security & Privacy pane.) In addition, you'll want to enable the Guest User account on your Mac so that someone can boot your Mac and run Safari, even with FileVault enabled--giving Find My Mac more time to reveal your Mac's location.
Theft-recovery software Whether or not you use Find My Mac, you can also install third-party software that tracks your Mac's location and even does things like snapping a photo with the built-in camera and taking a screenshot from time to time, the better to identify a thief. Possibilities include Orbicule's Undercover ($49), Hidden (starting at £1.25 per month), Fork's Prey (free), and GadgetTrak Laptop Security ($20). But bear in mind that none of these is compatible with FileVault, so if you want their extra recovery features, you'll have to forgo a fully encrypted disk.
There's nothing you can do prevent disasters from happening. But take these concrete steps and you can do something about the damage they cause.