Our September presenter, Peter Irish, Detective Constable in the Intelligence Division - Technological Crime, Toronto Police Service, opened our eyes to an increasingly complex and time consuming new frontier of police work.
He uses a number of free and open source apps that work just as well as, and sometimes better than, commercial products. For example, a free drive imager, FTK, includes full install, minimum portable, Linux and Mac versions. http://accessdata.com/support/adownloads
Peter also directed us to a web site containing 400 + Reviewed & Tested Free & Open Source Apps of every type & description: http://www.herouxapps.com/