Ask questions. I hate interviewing people that don't have any questions for me. Ask about their customers, history, financials, etc. Get the interviewer to talk about themselves too. People like to talk about themselves.

I don't worry too much if someone doesn't make much eye contact. I'm hiring software developers. I expect quirks and nervousness, especially in a job interview. I just need to see that they're capable of communicating with others without making everyone mad. It'd be a lot different if I were hiring in sales or consulting.