My recommendation is that applicants email thank you notes. Why? Everyone in academic medicine is now "connected" and checks email incessantly. Email communications also present the possibility of dialogue between you and your interviewer. An email thank you note can also be saved and filed. In contrast, a written thank you note may end up in your hard copy file (if the program/school prints out hard copies), but more often ends up in the garbage.
The only time you should consider writing a hand written note is if your interviewer seems "old school." For example, do you think this person works in an office that uses paper charts and has not yet converted to an electronic medical record system?
My clients have had great luck with email thank you notes; interviewers sometimes hit the reply button, acknowledge receipt, and express something positive. If, however, you do not receive a reply to your email, there is no need for concern.
If you are interested in working with me for the 2011/2012 application season, please contact me soon.
Visit: MedEdits