Look around your office. How many electrical devices do you have plugged in? Computers, audio/visual equipment, network devices, appliances, printers, and more. Now imagine if it was all rendered useless in a matter of seconds. That's exactly what can happen if you have an electrical surge. This doesn't have to be lightning. It can be a blown transformer or some other occurrence somewhere between the power plant and you. A high quality surge protector can help prevent this damage to your electrical equipment. There is an important distinction between a surge suppressor and a power strip. A power strip will allow you to plug additional devices in, but will not offer protection from a spike in electricity.
When you look for a good surge suppressor, pay attention to the UL certification. You'll want to make sure you get one that at least meets UL1449 specifications. A UL1449 rating means it is considered a "transient surge suppressor". Anything else will offer zero protection to your electronics. Also pay attention to the absorption rating. This is the amount of energy that the surge protector can withstand before it fails. The higher the number, the better. Look for one rated at least 700 joules. The clamping voltage is the number that determines when the protection kicks in. For this number, the lower the better. Look for one that's rated at 400V or less. Last but not least, make sure any surge suppressor you buy has enough outlets to be able to plug in your electronics. Pay special attention to the ones that have a little box on the end of the cord. These tend to take up 2-3 outlets on the surge protector unless you get one with spacing for that type of plug.
Some surge suppressors will offer a warranty that may provide some insurance if the device fails to protect your equipment. Make sure you read the documentation that comes with it to see if this is the case. Also, we recommend replacing all of your surge suppressors once in a while, as they may have been damaged by an earlier surge and may not offer the same protection they once did.