Is it a good idea to send a follow up letter or email to the person who interviewed you? I've read online that it is a good idea to thank them for their time and express an interest in the job and underline again your suitablility for the role. I've never done this before and am not sure if it would actually impress or annoy. Most likely my letter to them would probably cross in the post with their rejection letter to me leaving me feeling a bit of a berk. But still, might be worth a try. Anyone have thoughts on this?