It's a pretty simple idea, but hasn't been done yet (Upon further inspection, I've seen two other that haven't been updated in a while and have slightly different mechanics). This mod adds a misc item, Depleted Stealth Boy, to the player's inventory upon consumption of a Stealth Boy. The Depleted Stealth Boy can then be taken to a workbench along with a Fission Battery and a Science skill of 50 to make a Stealth Boy. Fallout 3 conversion (possibly) to come.