I picked up a bag of weed once, that someone had dropped, and smoked it. It wasn't much in terms of quality or quantity, but I took the risk and had no problems. I wouldn't do that today, as it was kind of reckless.

I wouldn't pick up a pipe. I don't use them anymore anyway, since getting a vaporizer.

I once found a 50 dollar bill in the NYC Lexington Avenue subway station. It was folded into a geometric, triangular shape. I sure as hell picked that up! My wife and I found two dollars on the sidewalk this past Saturday, that somebody had just lost. We took it.