Exiting Gracefully

Stand up and shake the interviewer's hand. Make eye contact and smile.
Thank the interviewer for his/her time, and restate your interest in the position.
Try to get a sense of their interest in you by asking, “How well do you think my skills and background fit the candidate you are looking for?” or, “How do you see me fitting in at the company?”
Interviewers will often say at the end of an interview, "You'll be contacted about next steps in the process." Don't read too much into that statement. It could mean that you will be scheduled for a second interview or it could mean that you will be notified that you are not the candidate they want. In short, it is an easy way for the interviewer to say something neutral at the end of the interview.
By all means, ask, "What is the next step in the process?" Most firms will indicate that they will be calling you.
Ask for a business card. Check to see if it has an e-mail address and ask if this would be an appropriate way to follow up, particularly if they don't say they will be calling you.
Ask them if it would be appropriate for you to call them, but don't expect a "yes" answer. Chances are, they would prefer to call you when a decision has been made.
Please don't skip step 8