This week's book giveaway is in the OCPJP forum. We're giving away four copies of OCA/OCP Java SE 7 Programmer I & II Study Guide and have Kathy Sierra & Bert Bates on-line! See this thread for details.
Probably you read wrong API documentation, in Java 1.2 & 1.4 Double had only one valueOf(String) method,
but starting from Java 5 Double class has two valueOf methods.
When you use google to find API docs, always add "Java 6" as keyword.