Just passed the OCWCD exam, I want to thank the Java Ranch guys for all the great posts they have for the this exam. I got a lot of help from various posts and at the end Enthuware tests helped a lot. They were quite like the real test and very good for practice. Head First Servlet and JSP was a really good book to prepare for this exam, I enjoyed reading it.
Over all the experience was good, but there was a fair bit of memorization of the API involved. Its not just logical concepts, you have to remember method names and return types. If anyone out there is preparing for the test, don't just skim over the text given in the book, memorize the API as well.