Originally posted here by tonybradley
Files containing hidden steganography messages are virtually undetectable.
Now I had thought that was true too.. until I read today groovicus's tut entitled "Windows Forensics-Where to look-What to use" found here

in that tut, groovicus mentions a tool called Stegdetect:
Capable of detecting several different steganographic methods to embed hidden information in JPEG images.

you can find more about Stegdetect here

Currently, the detectable schemes are
jsteg,
jphide (unix and windows),
invisible secrets,
outguess 01.3b,
F5 (header analysis),
appendX and camouflage.

heh.. not one month ago, I had told a friend about camouflage.. insisting it couldn't be detected.
WELL.. I guess I was wrong.. you learn something new everyday.. (thx, groovicus)