Check out Omnipelagos , a search engine that "finds the shortest paths between any two things."
It reminds me of the Six Degrees of Kevin Bacon trivia game  in which you tried to connect Kevin Bacon and any other actor through films or television shows the two worked on using no more than six steps.
Omnipelagos lets you enter two names or concepts and then connects the two. Here's a preset example I saw when I visited.
From Desperate Housewives to William Shakespeare:
set on Wisteria Lane in the fictional town of Fairview and written by Marc Cherry. The series tracks the lives of four housewives
Designing Women as Dixie Carter's personal assistant. In 1990 he became a writer and producer for the longrunning hit sitcom
A Winter's Tale by William Shakespeare. In 1967 she married businessman Arthur Carter (to whom she is not related)