Short Story based in the future

Morning, and what a beautiful blue morning in Birmingham it is!
I'm entering a short story competition where there is only one criteria - the story must be based anytime in the future.
Fantastic! I'll have a piece of that action. That offers the opportunity to come up with a premise that is truly original, I thought. So I sat down with a pen and paper (first pen didn't work, second pen leaked over my fingers - but the finer details aren't important right now) and started to scribble some notes, cross some out, write some more.
What if there has been a nuclear war and only a few people survive on a desolate land? Great idea! They could make that into a movie. No, hold on. Don't I remember Will Smith wandering with a big friendly dog on a desolate land? Damn those people in Hollywood.
What the characters are actually a clone of the real people? No, that was a Bruce Willis film.
What if a time machine is invented in the future that takes you back to the past? So like a double-bluff. No, that is too much like Back to the Future, and there will only ever be one Back to the Future (well, they made three, but you get the idea).
Or the universe has gone full circle so it appears the story is based in the past but really it is the future? Oh damn those hairy apes...!
And so it goes on,, and on. In fact, I probably droned on a bit too much already to emphasise the predicament.
Right now I am struggling to come up with an idea that has not already been recycled.
But I am going to keep writing down ideas on my pad, until something comes to me.
If you have any ideas, feel free to send me a message!