By the way, this is the best, most exhaustive discussion of Narcissism Personality Disorder that I've ever found online.
Narcissistic Personality Disorder (NPD) : How to Recognize a Narcissist
Check it out.
When I discussed this with a therapist, she said that the best way to interact with a narcissist is never, unless you must, in which case you should do with pity and from a great distance.