Originally Posted by
lwildernorva
Seconded. I haven't used anything but an adapter for my electronics in Europe for the last ten years and haven't fried a computer, tablet, cell phone, GPS, or anything else. Through several sources, I've heard that hair dryers aren't so reliably protected, but I don't use one of those normally unless the hotel/B&B provides it and then, it's only to dry clothes, not my hair.
as other people said, as long as your device says 110-240V, you can use a simple pin-head converter
if your device says only 110V (and the country you're going to uses 240V), you need a travel converter that steps the voltage up to 240V (or vice versa). This converter has a limit (eg 1000Watts).
Your hairdryer typically runs above 1000 Watts, so it's not good to plug into the travel converter and overload it