One must never underestimate the prescience of Ashton Kutcher. Critics panned his 2004 thriller The Butterfly Effect, but its title popularized an obscure concept of chaos theory--that small acts can beget far-flung consequences, as a butterfly's flapping its wings can trigger a storm thousands of miles away. Deep stuff for the guy who punk'd Justin Timberlake.
Two years later, we have a butterfly infestation: movies and TV are obsessed with stories about the random connections among vast, multinational and multilingual casts of strangers. Crash won the Best Picture Oscar for a story of multicultural Angelenos brought into conflict by circumstance. This year...