most peeps get nervous about talking in public places because they can't multi-task.
i.e, most of us can't think, talk, look at the audience and breath at the same time.
what is the solution?
Figure out what you want to say (for an interview, this means practice Q&A).
Breakdown it down into very small sentences like 5 word sentences.
Practice looking at mirror when saying your sentences.
Practice combing your hair, answering the questions and looking at the mirror

If all else fails, get laid. Regularly. Like every night.