I managed to get my Geiger counter together with my friend who is full of radioactive palladium the other day. Since we were outside, we were trying to find a slightly quieter place. There's a space between two buildings that has no windows, intended as a smoking area, so we walked into there and he stuck the counter probe pretty much down his pants and it started clattering wildly: nicely radioactive, easily detectable. Just as he did that, a guy in a suit walked out of the building and turned towards us, and my friend, in a very smooth move, swept the probe out and over towards one of the picnic benches there, and told the guy in the suit, "we're checking for radioactivity in the cigarette ashes!" He's smooth.