<p>I'm interested to know, because some colleges have contacted me about interviews.</p>
<p>My interviews have lasted anywhere from less than 30 minutes to almost 2 hours. Generally, though, they're like 45 minutes. You should be prepared to answer the "Why X College?" question, and you should try to give an answer that is more in depth and, ideally, is a reason that applies only to you. You usually also talk about your academics, such as what classes you are taking/took, extracurricular activities, interests, hobbies, and stuff along the lines of what you plan to do in the future (major, career, etc.) And be sure to come up with a few questions to ask the interviewer so it shows you've done your research and that you have interest in the school. You actually can learn a lot about a school from an interview. Most important, though however many times it has been mentioned, is just to be yourself. Stay calm (but exited), be well-mannered, and just enjoy.</p>
<p>^^Excellent advice!</p>