THE ANNIVERSARY PARTY — ** 1/2 — Jennifer Jason Leigh, Alan Cumming, Jennifer Beals, Kevin Kline, Phoebe Cates, Gwyneth Paltrow, Jane Addams, John C. Reilly, Mina Badie, Parker Posey, Denis O'Hare; rated R (profanity, drug use, nudity, vulgarity, brief sex); exclusively at the Tower Theatre.

It's one of the nastiest little ironies in Hollywood right now: Talented actors abound, and yet the quality — and overall creativity — of screenwriting is at an all-time low.

In fact, things have gotten so bad that sometimes you have to wonder why filmmakers don't just set up their camera in a room and simply turn cast members loose.

That's roughly the idea behind "The Anniversary Party," a film shot entirely on digital video that was purportedly written by its stars/co-directors Jennifer Jason Leigh and Alan Cumming. However, it's clear that much of this herky-jerky assemblage of scenes has been improvised by some of the duo's closest show-business friends.

The resulting film is mixed bag for sure — there are at least as many bad bits as there are good ones. And this is likely another example of a film that's too "inside" for mass consumption. (Not to mention that it seems to glorify recreational drug use, and there is a certain smugness to the material, which is off-putting).

Yet it's also got a prickly honesty, and it's nice to see some of these people getting the chance to shine, even if it is for just a moment.

As far as the movie's plot is concerned, it revolves around Joe Therrian and Sally Nash (Cumming and Leigh), a just-reconciled show-biz couple. He's a writer who's just been handed a plum directing gig (directing an adaptation of one of his novels), while she's a heading-for-middle-age actress whose work has been declining in quality.

Still, they're throwing a party to celebrate their sixth wedding anniversary, and have invited some of their closest friends. They include Sally's current co-star (Kevin Kline) and his now-retired actress-wife (Kline's real-life spouse Phoebe Cates), as well as Joe's childhood photographer friend (Jennifer Beals).

Also invited are Sky Davidson (Gwyneth Paltrow), the up-and-coming actress Joe hopes to cast in his movie, and the couple's uptight next-door neighbors (Denis O'Hare and Mina Badie), with whom they're trying to smooth things over.

So needless to say, it's a volatile mixture of friends and foes in their Hollywood Hills abode — one that's bound to get even worse when recreational drugs and petty jealousies are thrown into the mix.

As ambitious and promising an idea as this is, there's not nearly enough time to give all the members of this talented ensemble cast the forum each deserves (particularly underused are Cates and character-actor John C. Reilly).

Besides Cumming and Leigh, two who do impress are newcomers Badie and the multi-talented Michael Panes, whose resemblance to young Peter Sellers is remarkable.

"The Anniversary Party" is rated R for frequent use of strong profanity, scenes depicting drug use (marijuana and ecstacy), female nudity, use of crude sexual slang terms and some vulgar sex talk, and a brief scene of simulated sex. Running time: 115 minutes.