stegdetect
I take no credit for what is posted here. These are scripts for detecting images with stegnographically hidden data in them I found on 4chan.
Identify detected hidden files with: http://mark0.net/soft-trid-e.html or http://mark0.net/onlinetrid.aspx
For the windows script: https://dl.dropbox.com/u/21861447/gold-cli.jar http://dnsev.github.com/4cs/#about/codecs