I find nails and screws ALL THE TIME

And I always make a point to stop and pick them up. Even if I have to go over to the sidewalk for a minute and wait for it to be safe enough to stop and bend over in the middle of the travel lane.

I'm not just being a nice guy though. It's self serving because I drive my car on the same roads I bike commute on. I figure if I just leave a nail in the street for someone else to find, karma will make sure I'm the 'someone else'