Thumbtacks and Colored Strings

The accessories for tracking conspiracies and Love Dodecahedrons, especially before the computer era. One pins the photos to a board and then connects them with colour-coded strings.

Literature

 * Control by Victor Suvorov had it as a plot point. The protagonist set up such a board as her first project at the new job, to track the relationships between various bosses in Party, NKVD, etc and spot possible dangerous cabals. Her first conclusion was that this requires much larger cork panels.

Live-Action TV

 * Teen Wolf had a "crime board" set up by Stiles. The starting state of all strings is "unsolved".

Web Comics

 * Questionable Content, when Faye [//questionablecontent.net/view.php?comic=1089 tried to explain] relations within her circle of friends to a psychologist, the need arose.
 * xkcd meta-humour [//xkcd.com/2244/ presents] the "Attract Mode" for this game.