As some students struggle to understand why some with similar stats did or did not get similar admissions outcomes, this showed up on a facebook post as a bit of levity and a welcome relief from the sadness some shared. The comparative graphs are great! http://www.tylervigen.com/spurious-correlations. Per- capita consumption of mozzarella cheese and number of civil engineering doctorates? Letters in winning words of Scripps National Spelling bee and number of people killed by venomous spiders. Hysterical! Which do you like?
There is an xkcd comic showing how the dramatic rise in cancer diagnoses precedes the growth in cell phone use, concluding that based on actual data, cancer causes cell phones.
Hysterical.
Some of those correlations would be totally believable to me in a causal sense, if there were an appropriate time lag between the two elements. 
For example, I would not be at all surprised if arcade revenues the year someone is 16 correlated with the number of computer science Ph.D.s the year the same person is 25.