I discovered some new tools today that are useful for network security. QRadar from Q1 labs (http://www.q1labs.com/) is a really slick log parsing tool for organizations that are looking to implement a distributed log management offering to collect, archive, and analyze network and security event logs. It then parses this information into graphs and data that you can tune to alert you when things go awry. You can configure it to look at firewall logs, web server access logs, event logs, etc.
Splunk (http://www.splunk.com/) seems like it might be a competitor. At a glance, I'd say that QRadar has a lot more features and might be a lot more expensive.