1. safest measure is to unplug any appliance you can't afford to replace immediately when you aren't using it.
2. a quality UPS will keep your computer equipment/sewing machine running safely for a few minutes in the event of a power outage.
3. surge protecters work in a lot of mundance cases, but they are not 100% reliable or effective in the event of something major like a direct hit of lightening to your power or phone line.
4. it's as important - if not more important - to unplug your telephones and computer modems during an electric storm.
plain english. common sense.
what a concept.