Given that we are in the age of the Internet and along with it abject gullibility, here is an interesting page on how to detect photo fakery. Watch out for the REAL propagandists.

This would have been good for some to know a few days back regarding that faked Fox News/Obama clipmark. Oops.

Here's one for you. It was my very first clipmark here, and it is NOT a fake. : ) Seems some from NASA and quite a few Air Force ip addresses have been looking at it lately as well.

Another good clue is the Reuters tag on the photo. It's not 100%, but it is a good starting point.

Although I am at times weary of the entertainment-oriented fraud inherent in almost all media, I am guardedly hopeful that the pervasiveness today of subjectively modified or presented information may eventually serve to undermine the superficial, uncritical, and fundamentally materialist way in which we learn about the world around us.

Perhaps if we have to think a little more about what we are looking at rather than simply accepting it, we will discover much more of the intangible things that lurk in the world around us.

Wow, that was an awfully deep thought for this time in the morning. Think maybe it is past my bedtime.

NO kidding. I have to go eat my bran now. ; )

I would like to add to ouyandwulong''s comment by adding something just as profound:
Excellent clip Willhelm!