SafetyNET is my Intrusion Prevention System (IPS) project now in its fourth year of customer deployment. Human error has been engineered out and absolute security engineered in.
HORSE Project Wiki
My favorite pet project is the Holistic Operational Readiness Security Evaluation otherwise known as the HORSE Project. The intention is ultimately to raise the proficiency level of information security auditors, security practitioners, financial auditors, and anyone who verifies that controls exist over business systems.