Don't really know much about the challenge-But some of the problems seem to be time based?

Why not get people to send in their ideas for subject's and then post all the best subject's in advance---eg-Jan car's---Feb-space---Mrch-flowers  etc etc.

Everyone would have anything from one month to twelve month's to get their entries ready...

Just another silly idea.......

Equal right's for photographer's because i will be one - one day...................