Just read about this photo comp in the weekend australian, I am sure there are lots of photo comps but I dont know much about them, but these prizes seem pretty decent.
I immediately thought of the many excellent shutterbugs amongst the members of this fine forum
http://www.theweekendaustralian.com.au/photocomp/
EDIT: Just realised you got to have people in the shots LOL - should of read it bettter