The buzz had been building on Warner Bros. "The Hangover" for some time, but even the Burbank studio must be surprised after the Todd Phillips comedy grossed a stunning $16.5 million on its opening day. 

Featuring a relatively unknown cast of actors including Bradley Cooper, Ed Helms and Zach Galifianakis (who will be household names to many now), "The Hangover" is on track for anywhere from a $40-50 million weekend.  Considering the production budget was rumored to have hovered around only $30 million, the R-rated comedy is looking like a cash cow for the studio.  Whether it finishes number one, however, remains to be seen.

Coming in second place on Friday was Pixar's critically acclaimed "Up" with another $13.5 million for an impressive $106.5 million cume in just 10 days.  Because it's a family flick, "Up," could bump "Hangover" with Saturday's numbers and still win the weekend.  An intriguing story to watch for Sunday's estimates.

Disappointingly, the other big story of this weekend will be the mediocre results for the "Land of the Lost" reboot.  With only $7.2 million Friday, the Will Ferrell Sci-Fi comedy is looking at around $20-22 million for the weekend.  It's not a disaster, but Universal Studios, who made the film, reportedly was hoping for closer to $30 million.  Reviews have not been kind, but it's possible the release date hurt the picture's chance of a larger audience.  With "Up" and "Night at the Museum: Battle of the Smithsonian" already fighting for kiddies the family audience is split (and the PG-13 rating didn't help) and "The Hangover" surprisingly looked a lot hipper than the "Lost" reboot.  The picture is not a disaster on the scale of last year's "Semi-Pro" which grossed a total of $33 million, but it was a lot more expensive and a potential franchise for NBCUniversal.  Ferrell, who is up for a Tony Award on Sunday night, has not selected his next project and at this point in his movie career, it will be an important choice for the still popular comedian (when he's in the right project).

This is the second disappointing opening for Universal following last weekend's "Drag Me to Hell."  The studio will hope to rebound over the next six weeks with Johnny Depp's "Public Enemies," "Bruno" and the Adam Sandler/Seth Rogen dramedy "Funny People."

Also opening Friday was the Fox Searchlight romantic comedy "My Life in Ruins."  The first big screen role for "My Big Fat Greek Wedding" star Nia Vardalos since "Connie and Carla," the picture took in only $1 million in 1,164 theaters.

Look for final weekend numbers tomorrow on HitFix.  Here are Friday's results according to Box Office Mojo.

1. "The Hangover," $16.5 million

2. "Up," $13.5 million, $106.5 million to date.

3. "Land of the Lost," $7.2 million


4. "Night at the Museum: Battle of the Smithsonian," $2.5 million, $117 million to date.

5. "Drag Me to Hell," $2.5 million, $23 million to date.

6. "Terminator: Salvation,"$2.5 million, $99 million to date.

7. "Star Trek," $2.5 million, $216 million to date.

8. "Angels & Demons," $2 million, $111.6 million to date.

9. "My Life in Ruins," $1.1 million

10. "Dance Flick," $685,000, $21 million to date.