Many classic movies have been unafraid to ask the big questions — "How did we get here?" "What is the point of our existence?"

Others, such as "Hanging Up," manage to ask some decidedly less important questions — "What is the point of a movie this saccharine and superficial?"

Though it's slightly longer than 90 minutes, this interminable comedy feels at least twice as long. And what's worse, this cinematic equivalent of a prank phone call manages to waste the talents of a good cast in the process.

In fact, the film is so rambling, you'd swear the cast members were making it up as they go along — except that its story is based on a better-structured novel (by Delia Ephron, who co-wrote the script with her better-known sister, filmmaker Nora).

The threadbare storyline revolves around the three Mozell sisters: Georgia (Keaton), the controlling older sibling with her own media empire; Eve (Meg Ryan), the more responsible and caring middle sister; and Maddy (Lisa Kudrow), the youngest, who's on the verge of becoming a famous soap opera star.

Thanks to their careers, marriage and other major life events, the three have grown apart, though they still communicate by phone. That is, until fate conspires to bring them back together.

It seems their eccentric screenwriter father, Lou (Walter Matthau), has been hospitalized, due to a series of health problems, including a failing memory. He's been calling for them to visit and to find their mother (Cloris Leachman), who left him years ago.

Not too surprisingly, it's Eve who is the first (and only) one to respond. And as her father's condition deteriorates, Eve finds her life falling apart around her — though she is unwilling to ask her sisters for help.

You don't expect big plot surprises in such touchy-feely material as this, but what happens next is so familiar and so completely predictable that it makes those cookie-cutter movies made for the Lifetime cable network look like startlingly original works by comparison.

The script is the major culprit, but so are all the inept directorial decisions by Keaton, who plays everything as a lighthearted as possible, even when the material doesn't justify it.

So, perhaps it's not completely surprising that the cast seems so uninspired. Ryan's her usual sweet, froopy self — but that can't carry the picture, especially when Keaton and Kudrow give such two-dimensional performances.

But the person you really have to feel sorry for is the once-proud Matthau, who resorts to spouting vulgar sexual humor in a last-ditch attempt to scrounge up some needed laughs. Laughs that never come.

"Hanging Up" is rated PG-13 for profanity (including the so-called "R-rated" curse word), as well as some surprisingly crude jokes and sexual references.