Conclusion

Practical solutions to improve Cyber Security:
Privilege Separation
Used in OpenSSH, etc...

Intrusion Prevention
Systrace enforces security policies available for many Unix operating systems.

Threat Detection
Honeyd creates virtual honeypots to deter attackers and provides early warning and trend detection.

Software available freely under a BSD-license:
http://www.citi.umich.edu/u/provos/cybersecurity/