Dave Josephsen: Author of the Prentice Hall book: "Building a Monitoring Infrastructure with Nagios", Dave Josephsen is the Senior Systems Engineer for DBG, Inc., where he maintains a collection of geographically dispersed server farms. He has a decade of hands-on experience with Unix systems, routers, firewalls, and load balancers in support of complex, high-volume networks. He has nearly two decades of experience putting paper in printers, and over THREE decades of experience breathing. His co-authored work on Bayesian spam filtering earned a Best Paper award at USENIX LISA 2004. He has been published in both ;login and Sysadmin magazines on topics relating to security, systems monitoring and spam mitigation.