"I have this cool idea. If you could just help me write it..."

I just read an über-cool short story at Helix, "Rod Rapid and His Electric Chair" by John Barnes. It is truly scary (and funny) on a number of different levels, including a very nice twist of the knife at the end. What's very cool to me is the fact that the central plot device— forcing a criminal into a VR regression— is almost exactly the same as the one I used in "The Heavens Fall", and it's used narratively in almost the same way; and the story is completely different. The plot's different, the setting's different, the tone's different, the style is different, the outcome is way different, and the whole point of the story is different. Comparing the two should demonstrate why telling an author, "I got this real cool idea, if you could just help me write it," will only get you a wince and an amused nod at best.