To chime in on the tracing discussion:
Normally, for professional artists there is absolutely nothing wrong with tracing so long as the photo/work that you're tracing is your own. You certainly can't trace other people's photos because a photo is a work of art and that's plagiarism. You can always buy stock photos or use stock that is free, but unless you make some drastic changes to the composition etc, how much did you actually contribute to the piece?
A lot of time and effort goes into the preparation of a photorealistic painting. For example if you wanted to do a war scene, you could buy a plastic model of a tank, take photographs of it, rent world war 2 garb, shoot some models in said garb, travel to a field, photograph it, piece together a composition in photoshop, blow it up, line trace it, THEN paint it.
It's a lot of work...
Of course that doesn't apply to artists who may just draw all this stuff from their head or with minimal reference, because they're ridiculously talented.
But for the rest of us... lot's of prep.
But yeah, I'm not talking down any of the pieces in this contest. After all, it was stated in the rules that tracing photos from the internet is fine, and it's just for practice/fun anyway.