And the Box Office Champion this week is...

The analysts and studio executives who are bullish on the prospects for 3-D over the next few years will point to this past weekend as evidence that they're onto something. Monsters Vs. Aliens, the 3-D release by DreamWorks Animation, topped North American box office results with $58.2 million in sales over the weekend. The movie, distributed by Paramount, opened on Friday on over 7,000 screens, with about 2,000 of them equipped for 3-D broadcast. About 56 percent of total ticket sales were for 3-D tickets, which cost $2 to $4 more than regular tickets.

Piper Jaffray analyst James Marsh believes that 3-D ticket sales in theaters will grow to $3.9 billion in 2011?or about a third of all box-office revenues?from a small base last year; 3-D will increase movie attendance by 20 percent to 25 percent, he says. Monsters Vs. Aliens didn't top DreamWorks Animation's last two releases, Kung Fu Panda and a Madagascar sequel, which brought in $60 million and $63 million respectively at the box office during their opening weekends. Still, 3-D tickets were sold out, and according to The Wall Street Journal , 40 percent of those who bought 2-D tickets said in exit polls that they would have preferred to buy 3-D tickets. In the movie, a meteor turns some humans into monsters who then have to protect the human world from an alien attack.

While 3-D looks has gotten off to a strong start?there have been a smattering of releases until now but studios are ramping up their 3-D production this year?many theater chains have yet to install the technology in their theaters; fewer than 5 percent are equipped with 3-D systems, and the poor economy may further slow that adoption. The next slate of 3-D releases?Disney's Up and Fox's Avatar?will hit theaters over the next few months.