Lens cap ethics....

An odd thing happened on my dawn walk with the spaniel this morning. Crossing the common in driving rain and wind I found not one, not two but three lost lens caps within a space of 20 minutes or so. Even odder was the fact that they came in alphabetical order, Nikon, Olympus and Pentax and were all the same (52mm) diameter. I don't think I've ever found a lost lens cap on the commons before. None of them were particularly muddy (although the Pentax one is a bit scratched) so it seems they must all have been lost fairly recently.

Here's my dilemma: what should you do with a lost lens cap (or caps)? Do you leave it where it is and assume the owner (or probably owners in this case) will eventually retrace their steps and recover the lens cap (I know I've done that several times myself, as well as tripod - still standing where I'd left it two days later), or do you retrieve them and put them in a prominent location? What's the etiquette here?

Given the weather, the first scenario seemed somewhat unlikely so I've opted for the second, placing them in a see-through bag pinned to the noticeboard in the car park. There is of course no guarantee that the owners arrived by car ....

I replaced my original, unispiring image with this one of the alder bracket fungi, taken later in the day when the sun came out.