Small things

A few quick tips:

1. Be mindful of what you do with your right hand during an interview.  Sounds creepy, but you're going to shake hands with someone that is interviewing you.  It can distract an interviewer if you're coughing into your hand, sneezing into it, wiping your mouth, etc.  It's tough for someone to concentrate on your answers when they're imagining shaking that hand afterwards.
2. Always ask for a business card when you're at an interview.  How else are you going to follow up?  I've seen so many people forget the name of the person interviewing them once they walk out.
3. Make a phone call if you're going to be late, even if it's only a few minutes.