This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
Such a reverse look-up doesn't really make sense to me. In your example the currency symbol "$" is used to signify the US Dollar in the en_US locale, en_CA and nl_NL locale, to name just a few. Moreover, in the same locales it is also used to signify not only the US Dollar, but the Canadian Dollar, New Zealand Dollar, and many other currencies. Anyway, since this is not threading related, I'm moving this to Java in General.
Build a man a fire, and he'll be warm for a day. Set a man on fire, and he'll be warm for the rest of his life.