B.O. FORECAST: Wil-maaaaaa!

Yabba Dabba Doo? Or, Yabba Dabba Don’t?

That’s the dilemma facing moviegoers this weekend, as they try to choose among “The Flintstones in Viva Rock Vegas” and two other big new releases, “Frequency” and “Where the Heart Is.”

Though lacking the star power of its 1994 predecessor, “The Flintstones” (which featured John Goodman, Rosie O’Donnell, Elizabeth Taylor and Halle Berry), the prehistoric flick is the only new film aimed at kids (the other two are about dead parents and teen pregnancy, respectively), which might give it a brontosaurus-burger-sized advantage at the box office.

Here’s a look at this weekend’s new releases:

“Viva Rock Vegas” THE FLINTSTONES IN VIVA ROCK VEGAS (See the trailer) The skinny: This prequel to “The Flintstones” follows young Fred and Wilma and Barney and Betty to Rock Vegas (Get it? Get it?) for a joint wedding. As they say, hijinx ensue. The upside: The movie reveals (or, more likely, makes up) lots of new Flintstone trivia, such as Wilma’s maiden name (Slaghoople). The downside: The biggest name in the cast is (dramatic pause): Joan Collins! “Frequency

FREQUENCY (See the trailer) The skinny: Dennis Quaid plays a dead dad who communicates with his grown son (James Caviezel) from the afterlife via an old ham-radio set. Says Paul Dergarabedian of the box-office tracking firm Exhibitor Relations: “It may be a film that builds momentum over the coming weeks, as people tell their friends about it.” The upside: It’s got it all: Immortality, mystery, action, suspense and family values. The downside: Ham radios in heaven? You’d think they’d have cell phones by now.

WHERE THE HEART IS The skinny: Pregnant teen Natalie Portman gets dumped at an Oklahoma Wal-Mart by her boyfriend. The locals (including Ashley Judd) take her in. The upside: Yet another entry in the recent string of “troubled daughter/weird mother” chick flicks, minus the weird mother part. The downside: Natalie Portman‘s not supposed to get pregnant until the next “Star Wars” movie, when she does it with Darth Vader and gives birth to Luke Skywalker. The new entries will contend with the reigning No. 1 film, “U-571,” and with several other recent box-office champs such as “Rules of Engagement” and “Erin Brockovich,” all of which can be expected to remain in Top 10 contention.

U-571 is still benefiting from good word-of-mouth, so I suspect it won’t drop very much,” says Dergarabedian. “It’s likely to make another $13 or $14 million, so any of these openers are going to have to make more than that, in order to contend for the No. 1 spot.”

However, all bets are off next weekend, when the big-budget, big-hyped “Gladiator” opens.