May 1 is the deadline for The First Line's Summer issue. The starter sentence is quite intriguing, "I started collecting secrets when I was six years old." I also thought how easy it would be to replace secrets with something else, like fingers or knives, if you'd like to write a story about the birth of a serial killer or a mercenary. Or perhaps she was collecting fairies or magic or falling stars. You get my drift, any sentence can be made into a prompt just by the changing of a simple word. Your story is just a switched out word away.
Oh yes, and The First Line is a paying print market that accepts stories in any genre. You just have to start your story with their sentence. Besides this sentence there are two more posted for 2013.