This is why Vince Vaughn is known as box office gold.  A typical Vaughn comedy has a reasonable price tag and reaps big returns... if not always big laughs.  The actor made the new bosses over at Universal very happy on Friday as "Couples Retreat" opened to over $12.3 million from 3,000 screens.  It didn't hurt that the PG-13 comedy was the only wide release of the week, of course.  Meanwhile, Sony is still feeling the love with "Zombieland" at number two and their 3D toon-that-could, "Cloudy With a Chance of Meatballs", losing little monetary momentum at number three.  But the real momentum this week belongs to Paramount.  The studio's indie horror pick-up "Paranormal Activity" moved from midnight-only screenings in a handful of cities to 159 venues (at all hours) on Friday.  With marketing being handled mainly by fans and social networkers, the studio can just sit back and count the cash as it rolls in.  Already the $11,000 pic has earned $3.7 million total.  Check back tomorrow to see exactly how much word-of-mouth will be worth this time.