I don't know how often these happen anymore, but phone interviews can be tricky. Some companies use phone interviews as their first (preliminary) interview to see if they are interested in taking the time to sit down and meet with you. I did, however, get my internship after a phone interview.
For me, the key is to be prepared. I kept my resume in front of me during as well as a note pad to jot down notes and key points of the interview. It’s harder to read people's emotions through the phone, since something like 85% of our communication is nonverbal. Its important to pay attention to the tone in your interviewer's voice and that can give you a decent read. It is important to speak clearly and at a decent pace, my main problem is when I get nervous I tend to talk too fast and stumble over my words or jumble them together. It is important to feel comfortable and confident even if they can't see it they can sense it in your voice.
It is usually best to conduct phone interviews from a landline, so you don't have to worry about dropped calls and static. I would also say to try and do it in a quiet area to ensure you have the best chance not to miss anything. As in any interview you always want to say what you mean and mean what you say. Also choose your words wisely, it can be difficult to move away from the way you normally speak (the use of slang and the word like) but it is important to sound professional, especially since they cannot see you.
All and all along with the professional side shining through you should always remember to let a little bit of your personality show, making it a little personal will help the interviewer get to know the real you and help them see if you are the addition they are looking for.
-K