Dear ... 
It was very enjoyable to speak with you today about the __(type of posistion)__ position available at __(name of organization)__.  I am very excited about this position and believe that my skills and interests are a good match with your requirements. 
In addition to my experience, skills and qualifications, I am a team player who brings enthusiasm and unique concepts into a group environment.  I am certain that I have what it takes to bring the kind of energy and dedication that you are looking for in this position.  I really believe that I could make an immediate positive contribution to your team. 
Thank you for the time you took to interview me. I was truly inspired by the interview and I am very interested in working with you.  I look forward to hearing from soon with your decision.  
Sincerely,