I'm reading For My Eyes Only, John Glen's memoir about his career and especially as director of all the '80s Bond movies, and I love this piece about Christopher Walken ("A View to a Kill"):
"The only problem I had working with Christopher was his habit of wandering off while we were on location. I'd turn my back for a moment, only to discover that he'd gone for a walk somewhere. I ended up giving one of the junior assistant directors the sole responsibility of keeping an eye on Christopher and making sure he was around when I needed him for a shot. This became something of a game for Christopher and as soon as this guy was distracted for a second, he'd nip off in the other direction."