“Towards Better Usability, Security and Privacy of Information Technology” is a great survey of the state of usable security and privacy:
Usability has emerged as a significant issue in ensuring the security and privacy of computer systems. More-usable security can help avoid the inadvertent (or even deliberate) undermining of security by users. Indeed, without sufficient usability to accomplish tasks efficiently and with less effort, users will often tend to bypass security features. A small but growing community of researchers, with roots in such fields as human-computer interaction, psychology, and computer security, has been conducting research in this area.
Regardless of how familiar you are with usable security, this report is a worthwhile read.