We recently added Splunk to our free tools section on Thwack. http://thwack.com/freetools/ The Splunk guys describe their product as "the IT Search Engine", but it seems difficult to easily describe. Many people use it as a data aggregator and slick search engine for any type of network device logs, but it has a lot more functionality than that.
Are there any SolarWinds people out there that have heard of Splunk, use it, or perhaps even use it with Orion?