My latest terrain score (also known as another reason my wife wants to kill me), eight of these babies:
Old (and broken) heads for an in-ground sprinkler system. After some cleaning, some judicous use of a cutting wheel, and some careful disassembly, you get these:
The assembly that drew me to these to begin with:
Other bits - a basket filter, some internal bits I can leverage to a sensor array of some sort, and the rest of the casing, probably destined to be a support pillar:
Best part? They're $55 a piece new. These were destined for the trash, and free.