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.
They are. However, sometimes you want to use a different kind of ordering, and ignore the compareTo method. Or the objects you want to sort are not Comparable and you can't make them Comparable. If either is the case, you have to use a Comparator.