One of the more fun parts (if there can be one when dealing with a compromise) is figuring out what happened and how did it happen.  Fellow handler Mari Nichols already addressed the topic of Gathering Evidence That can Be Used in Court.  Now it's time to think about tools that can be used to aid in helping solve the mystery of what happened.  Forensics is a fun and fascinating field with many tools out there to choose from.  Do you prefer Open Source tools such as The Sleuth Kit (TSK) or perhaps a commercial version of a tool such as EnCase? 

However, let's don't restrict our thoughts to tools that deal with just computer hard drives.  So many devices are out there that lend themselves to being compromised or used in a compromise such as blackberries, printers, routers etc.  What tools do you use when doing forensics on these devices if they were used in the compromise or were perhaps compromised themselves? 

If you have a good suggestion for a tool that has served you well or lessons learned from one, please pass it along.  Also, if you have had to do forensics on a device, other than a typical computer harddrive and found a tool that worked, please pass it along as well!  Its a great opportunity to share and your experiences may be able to help someone else in a similar situation!