I've never used this product so I can't recommend it, but PA is offering a free (as in beer) trial (a sip) of its Network Forensic Search Engine (Net/FSE) -- a tool used to collect and perform analysis of network alert data.
If anyone snags a copy or has used it in the past, please let the rest of us know your experience, thanks!
http://www.packetanalytics.com/download.php
Forensics : Working for the dark side
