And of course, you should include high-quality surge protectors or UPSs on all high-tech equipment for protection against power surges and lightning strikes.
You can replace computer equipment, but that costs money. And if your business is out of commission for a month or two while you rebuild from a fire, you won't be earning anything along the way. That problem can destroy a company that might withstand the physical damage caused by a disaster.
Generally, insurance is the best safeguard against financial ruin. Standard property insurance will cover the loss of hardware, but business interruption insurance is essential if you want a safety net to preserve your company against lost sales.
One other component of your small business needs to be protected: you. Do you want your business continue to operate after you've shuffled off this mortal coil? If the plan is to shut it down, how will that happen? How will ongoing ownership issues be determined? Who's going to run the show?
These are complicated issues that any small-business owner should discuss with a qualified estate planner to resolve, and any protégés being groomed to take over when you're gone need to be aware of the plans well in advance. Software such as Quicken WillMaker steps an individual through basic estate planning. It's a serious subject, but tackling the creation of a will and a succession plan while you're young and healthy is far better than waiting until you're lying in a hospital bed. Make it a priority to create a continuity plan (or a dissolution plan, if you aren't going to pass the business along to an heir), and revisit it annually to ensure that it's up to snuff.