Speaking of ten-by-ten grids and synchronous short stories, back in February I had the idea of writing a story in a hundred different ways, a hundred words each. Yes, I think about this sort of thing all the time.
I called the project 10x10x100, and each hundred words was going to tell some aspect of the same ten seconds of time. There would be ten different styles and ten different locations, and the reader wouldn't know for some time (a) what the story was about and (b) how it would resolve. I got around eleven stories into it and then started scratching my head about how to continue. It needed some core energy that I just couldn't develop and harness, so I took a rest from it—pretty disconsolate, to be honest, as I had no other ideas for A Pocketful of Lies #3 at that time—and started casting around for other ideas.
It's still on the back burner, and I think I could see how to finish it if I returned to it now, but as you've probably guessed by now it's not what I'm doing this Christmas. Oh, the suspense!