I do as I've fried things on my computer and DSL even though it goes through a surge protector and battery back up box. Even our telephone has gotten fried so I even unplug that from the wall.

Yes, that's definitely a good idea, unless you have a good surge protector, well, even then, if it's a really strong storm, unplug it if it's not a hassle. Even if it's not an EMP, a lighting bolt does of a chance of hitting your power lines, thus, making the chance to fry you computer.

It's a very good idea. Even with a surge protector, a storm can end up frying your equipment.

Let's be clear -- it's not EMP (electro-magnetic pulse), it's an electrical surge. There are two things that can kill your equipment: Surge, where voltage levels spike above normal, and a low-voltage condition, where voltage levels sag below normal. Surge protectors (NOT POWER STRIPS) have electronic circuitry designed to protect equipment based on a certain load. They are sometimes designed with circuit breakers, or they just fry to prevent the equipment from being damaged. A power strip just connects multiple outlets together, and is like a glorified extension cord. Some power strips have circuit breakers, which do not look at voltage at all -- circuit breakers are designed to disconnect when a certain amount of power is applied. By the time the breaker opens, TOO LATE. A good surge protector comes with an equipment guarantee, usually up to around $10,000 -- meaning if you are using the product as intended, and you incur damage (even during an electrical storm) the manufacturer pays for your stuff (up to the limit of the guarantee). I exclusively use APC products for my TV, stereo, PC, etc... www.apc.com I have the computer on UPS, because I find that it's helpful to look at weather.com for real-time storm info, even when the power is out. (Also handy for running low-power LED task lights during a power outage) All of this assumes your electrical wiring is properly grounded. Get a cheap outlet tester, around $5, with three or four lights that light up telling you if everything is OK, or if there is a specific problem (e.g. ground short). If you have a ground short or if you have no ground at all, you run more of a risk of damaging your equipment (and the surge protector manufacturer won't honor the guarantee). So if that's the case, call a licensed electrician to fix the problem.