Six Degrees of Wikipedia was a 2006 web sensation, racking up the Diggs and making the Telegraph. This application would tell you how closely Wikipedia entries were related (Viagra and mackerel? Four degrees.)
The Six Degrees machine is not working right now. So my friend Evan Schiller proposed a lower-tech version (similar to games going on in message board land), which we've been playing on and off all afternoon. Our last game started with the Holden VE Commodore, with the goal to reach Ridley Scott in the fewest clicks/links. (Holden VE Commodore --> United Kingdom --> Cinema of the United Kingdom --> Ridley Scott. I win.)
Anyone bored enough to participate?