Found this just googling for writing prompts and it caught my eye. The prompt comes from here:
This category contains the results of my writing for at least twenty minutes on a given prompt. The prompts can come from anywhere, but I think I am going to try to work through someone’s book. If possible, I will include the prompt, or at least a synopsis of the prompt, at the beginning of the post. Some of these prompt writers can go on and on.