I found the mock exam list at java ranch (http://www.javaranch.com/mock.jsp), but was a bit annoyed when I noticed this list is really very much out of date. We're at java version 1.5 now, and most exams are about version 1.2 and some even on version 1.1. You guys are several versions behind!!! Isn't there a recent list of recent mock exams??
Actually I think the javaranch mock exam list is one of the most comprehensive (though the exams themselves may not be the all 1.5) list on the web. When I clicked on one of the older exams such as 1.4 and I encounter a question that I know should not be in 1.5 anymore, I'll just skip over it. Even skipping the older version questions (such as those on AWT), a lot of the mock exam questions are still useful for practicing.
Many of these sites in the list is well organized too, with separate page answers and detailed explanations. I find it very useful as assisting with more practice in addition to the K&B self test and sample exam questions. Of course, if you buy the commercial mock exam kits they are probably more up-to-date, but this free list basically contains more than enough practice questions.
In fact I only use the K&B book and this mock exam list...