Extra copies of your resume.

Yes, in theory your interviewer should have a copy of your resume when you show up, but don't let the interviewer's lack of preparation become your lack of preparation. Keep multiple copies on hand just in case the person you're speaking with forgot to bring it in. Alternatively, you may find that you're talking to multiple people during the interview, which case these individuals may have never seen your resume before. Even in the best case scenario in which every person shows up to the interview holding a copy of your life in their hands, it's still a good idea to bring extra copies for yourself! When you show up to an interview, you're nervous, and it's easy to freeze up or forget about the finer details of your past. Having a copy of your work history in front of you keeps you on track and cuts down on those embarrassing, awkward pauses.

An organized list of references with a heading designating them as such.

While an employer may not require this until a later date, or may not require it at all, it's still a great idea to bring a list of names and numbers of people who will vouch for you. First, you are taking the initiative by voluntarily providing this information. Second, it conveys confidence in your abilities when you invite an employer to contact others on your behalf.

Legal pad and pens.

Oftentimes in an interview, a moment may come up where you may want to write down a few notes about the company or position. This might be for your own records, or it may be helpful in remembering key details for a follow-up email or thank you note.

Think of this list as your portfolio survival kit. Your supplies: resume, references, and Writing supplies. Carrying all of these documents in a portfolio always makes a professional impression.