I am a member of a popular photo contest web sight, that I love, inspi.re. One of the rules in many of the groups is no post processing. I understand this rule to some degree, some of us don't have the necessary software, and this levels the playing field. ... but almost every camera comes w/ some kind of software, so we should have no excuse. And I also understand totaly rules that exclude composting (I think thats what its called when you combine elements from multiple photos) and digital art.
Let me make a film analogy or two to this rule to help you understand why I think these rules are silly. What if you had to enter a contest where you could only use prints from a 1 hour photo no custom printing in your darkroom. Or perhaps you wanted to show your work at a gallery but they only exhibit slides. Do you understand where I am coming from. Expecting you to compete w/ in camera results only is taking away from your vision, the moment that you imagined when you pressed the shutter.Your camera just can't capture things the way that your eyes see them and then your brain processes them. So the images always need a little help. now I am not saying that you shouldn't do everything you can to get the best shot possible in camera. I believe that the most important step in your work flow is to get it right in camera, this will save you loads of time and lead to much better end results. But well you know.