a4j (Amazon web services for Java) is a Free Open Source API, that makes it easier to access Amazons product catalog. It is perfect for Amazon affiliates. It provides the developer an easy to use API to search the Amazon catalog. It will connect to Amazon get the XML file, parse it and return to you an easy to use Java Bean. It does all of the hard work for the developer, so that the developer can concentrate on more important things. It supports caching, so it won't have to always connect to Amazon to get the information, which means it is much faster. Try it out and let the author know what you think!