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.
Beware of instanceof. When you find yourself querying the type of an object, you should wonder whether you have made a design mistake. In this case you are obviously using it to find out how the operator works, which is always all right.