Foremost: a Linux computer forensics tool
 "Written by agents in the U.S. Air Force Office of Special Investigations, Foremost can read 
through files and file headers on PCs or copied PC hard disk images. The tool scans a drive or 
drive image for pre-defined file types or specific text strings, which are defined in a 
configuration file. Foremost can be used to recover entire files, or partial file fragments from a 
damaged disk as well as from deleted files on a hard drive. When the program finds files, it copies 
the file header and data to a file on the local Linux machine."
Story

http://rootprompt.org/article.php3?article=7117

For stuff like Jim Hermann's lost mail it should be useful too.

Brian Kelsay