If I remember one thing about you, what should it be?

Before you answer this question, take a good hard look at the job posting for the position that you are interviewing for. Now, here are your two choices for preparing your answer:

• Desired skill that they want that you have. Take a moment to reiterate that you possess this skills, whether it is teaching, program development or reference experience, stress how you can fulfill this need.
• Desired soft skill that they want. Do they want team players? Collegial? Committed to learning? Do you have any of those traits? How can you show them and why do you think you could demonstrate them here. Do not underestimate the power of a soft skill: if this is an entry-level position, all of the candidates should possess the requisite hard skills for the position. Therefore, the question is one of "fit": whose personality do we like best?

This is not a plea for a job time. This is stressing how you fit, either personality-wise or skills-wise.

And though some interview books may suggest that you talk about how this job fits with your career path, I would advise against that response. You want them to remember you not for what you will get out of the job, but for what they will get out of you.