The Lost Art of Thank You Notes
Never underestimate the impact of a courtesy thank you note. Most candidates neglect this most basic component of Emily Post etiquette. Make sure you have the interviewers business card so you can thank them for your time. The best form of thank you is a note mailed directly. However, if you know the decision to hire is imminent, do not rely upon the postal service, send it via email. Your best bet is to send one the following morning. Be sure to mention your interest in the role and emphasize any areas that may have remained in question during the interview. Send thank you's to all the people you met and spent any one-on-one time with.

Don't forget KBW !
If a recruiter has coordinated an interview for you, call them back immediately following the interview to share your feedback with them. It is also a good idea to thank recruiters for their time when interviewing with them... most candidates don't so it's a great way to promote yourself by indicating your interest in working together and showcasing that you will represent them well.