On a Mac, at least, the £ symbol is "option+#," and I know there's a euro symbol available with some keystroke or other.

As far as I know, all notebooks automatically adjust to whatever electric current is available.

Before taking my Macbook to the UK, I asked at the Apple store, and they assured me that all I needed was a UK-compatible plug for the power block, and that turned out to be true.

My computer barely knew it was away from home.