Where Should I Get My Job Interview Code Samples?

crlove asks: "I'm preparing for an upcoming job interview and my interviewer will want to see some code samples. Unfortunately, all of the coding I've done work-wise since college is not only proprietary, but often classified. To be honest, with long days at work and a busy life outside of it, I haven't had much time to code on my own. So, what should I show my interviewer? Should I start working up some code samples? If so, what would be considered sufficiently complex to take to an interview?"