Ummm... the point of interview questions is to find out what you know, not what you think you want the interviewer to believe you know. If the interviewer has any neurons firing they aren't going to just feed you stock questions and wait for stock answers. Try to work with JUnit to do some obvious-but-nontrivial things like verify that the state of some database tables changed the way you expected your code to change them, or compare an expected XML document to the one produced by your code. If you can do those two things, you can probably cope with test-related interview questions.
The point is, tell the interviewer things you *KNOW*. Companies have developers that they toss into interviews or phone screens just to weed out people who think prepping a few interview questions will get them any job. Any company that does that won't be fooled by you. Any company that doesn't do that isn't worth working for. [ January 13, 2006: Message edited by: Reid M. Pinchback ]
Some common testing questions: 1. If you were the test manager, how would you direct the testing of a site like amazon.com or ebay.com 2. Describe the importance of a good QA infrastructure to a software company. 3. Talk about some testing tools that you have used. (make sure you are familiar with Junit and some record-play tools like RationalRobot) 4. How would you develop a performance testing strategy without using an expensive tool. 5. Elaborate more on performance related issues for web based applications and come up with a comprehensive test suite.