Here's the deal. for your laptop because there's already a converter built in, all you need is an adaptor. The same is true for your cell phone. For a hairdryer, you need something that does both. Personally, I think you are better off buying a $10 portable hairdryer for the time you are in Europe. The Americans, even with the adaptor converter can still blow the fuse in an older hotel. Also some hotels now have one built in to the wall.
Houndentenor
"Get the trash off the street and back on the stage where it belongs." -- Bette Midler