Lately I've started wondering about the ¤ character which is shift+4 on my Norwegian keyboard (it's also present on several others, including the U.S. International keyboard layout). I've never seen a use for it, yet for some reason someone decided it was important enough to have it put in such a central place on the keyboard. What is this character called, and what purpose does it have?
This is the currency sign
A currency sign is a graphic symbol used as a shorthand for a currency's name.
Also from Currency (typography):
The currency sign (¤) is a character used to denote a currency, when the symbol for a particular currency is unavailable.
The symbol is available on some keyboard layouts, for example French, Danish, Norwegian, Swedish and Finnish keyboards, because it is used in business applications.