By BUCK WOLF

June 21, 2005 — How should the world react when Katie Holmes says that she had a poster of Tom Cruise in her bedroom when she was a little girl?

On one level, it's no big deal. After all, Holmes was 8 years old in 1986, when Cruise was starring in "Top Gun." It was the right time for a crush. Many little girls dream of marrying their favorite movie star. That's just natural.

• Celebrity Couples With an Age Gap

What's unnatural, it seems, is that Holmes is close to fulfilling that notion. Why, just thinking about it could get me jumping up and down on Oprah's couch … and I date women my own age.

In the twisted world of Hollywood romance, giant age gaps are not too uncommon. In fact, the 16 years that separate the 42-year-old Cruise and his would-be third wife are nothing compared to the 25-year age difference between Humphrey Bogart and Lauren Bacall, and things seemed to work out for them.

Let's take a look at how major age gaps affected some of the most celebrated affairs in Hollywood history.

Giant Age Gap Romances

1.Tony Randall and Heather Harlan (50 Years)

Heather Harlan, Tony Randall's second wife, was born in 1970, the same year Randall rocketed to TV immortality as America's favorite fussbudget, Felix Unger.

Twenty-five years later, Harlan married a 75-year-old Randall, and they became a real-life "Odd Couple."

The 1995 marriage drew headlines, and Randall got ribbed, even by friends, for being a dinosaur dad. At 77, he became a first-time father, and welcomed his second child three years later.

Nevertheless, Randall hardly fit the description of a showbiz playboy. He'd been married for 54 years to Florence Goss, his high school sweetheart, who died of cancer three years before he and Harlan met.

Randall died last year, about six months before he and Harlan could celebrate their ninth anniversary. She is now raising their two children.

2. Groucho Marx and Eden Hartford (40 Years)

"Marriage is a wonderful institution," Groucho Marx once noted. "But who wants to live in an institution?"

In all likelihood, the great comedian looked upon marriage as nothing but fodder for stage material. The world-famous pessimist was especially pessimistic about celebrity romance.

"Hollywood brides keep their bouquets and throw away the grooms," Groucho quipped.

In 1954, Groucho exchanged vows with his third wife, Eden Hartford. She was 24, and he was a year away from qualifying for Social Security. "A man is only as young as the woman he feels," he said.

The marriage lasted 15 years, and it was one of the most productive periods in Groucho's life, when he successfully made the jump to TV host, as the star of the long-running hit, "You Bet Your Life." Hartford became the only ex-wife Groucho remained friendly with later in life. He'd continue to keep young companions until his death in 1977.

3. Woody Allen and Soon-Yi Previn (35 Years)

Interestingly, big screen action heroes aren't Hollywood's greatest marital adventurers. Comedians account for some of the wildest May-December relationships.

Charlie Chaplin was 54 when he married Oona O'Neill, the 17-year-old daughter of playwright Eugene O'Neill. They had eight children and remained together for 34 years, until his death, in 1977.

Then there's Woody Allen and his current wife, Soon-Yi Previn. They met, of course, when Allen dated Previn's mother, Mia Farrow.

The South Korea-born Previn was one of nine children Farrow had adopted at the time she dated Allen. She and Allen adopted two of those children together, and had another biologically.

In 1992, with their relationship waning, Farrow found nude pictures of Previn, then 22, in Allen's apartment. A furious Farrow called for an investigation of child misconduct, but no criminal charges were brought against the comedian.

Five years later, after celebrating his 62nd birthday, Allen and his 27-year-old girlfriend married. They are now raising two children, in addition to the children Allen has helped to raise with his wife's mother.

"I sold the story of my sex life to Parker Brothers and they're making a game out of it," Woody Allen quipped to reporters in the heat of his marital controversy.

4. Robert Evans and Catherine Oxenberg (32 years)

A giant age gap is at the heart of one of Hollywood's shortest marriages — a union that lasted just nine days.

In July 1998, famed producer Robert Evans became smitten with 36-year-old actress Catherine Oxenberg, who played Joan Collins' daughter on "Dynasty" and appeared twice as Princess Diana in TV movies.

At the time of their meeting, the 68-year-old Evans had a weak heart and was writing a book about his near-death experience, "I Heard the Fat Lady Sing."

In a little over a week, the marriage was annulled, and neither side would elaborate in detail about the circumstances. "I forgot it had only been six weeks since I had been hit with a stroke," Evans later told the showbiz newspaper Variety.

Evans, now 74, recently produced the Kate Hudson comedy, "How to Lose a Guy in 10 Days," a film that had nothing to do with his time with Oxenberg, though the film title might suggest otherwise.

5. Frank Sinatra and Mia Farrow (29 years)

After two failed marriages and a string of romances with the likes of Lana Turner and Marilyn Monroe, legendary lothario Frank Sinatra tied the knot in 1966 with Mia Farrow. She was 21. He was 50. It ended two years later, after he began an affair with Lee Remick.

In 1970, Farrow married conductor André Previn, and after eight years together, they divorced. By the early 1980s, Farrow began appearing in Woody Allen comedies. And the rest, to Farrow's regret, is history.

6. Humphrey Bogart and Lauren Bacall (25 years)

"Here's looking at you, kid." Humphrey Bogart could have used his immortal "Casablanca" line with Lauren Bacall and meant it literally. Next to him, she really was a kid.

Bogey was six years into his third marriage when he fell in love with Bacall, during the production of 1944's "To Have and Have Not." He was 45 and one of the most powerful men in Hollywood. She was a 20-year-old starlet making her big screen debut.

Just to show you how a celebrity romance, even then, could trump everything else, this film was based on a story by Ernest Hemingway. The screenplay was co-written by William Faulkner. But still, Bacall's part was expanded midway through production because the budding romance was grabbing headlines.

Bogart barely waited for the ink to dry on his divorce papers before sailing away to "Key Largo." On May 21, 1945, 11 days after the court papers came through, he married Bacall. They had two children, and remained together until his death in 1957.

7. Michael Douglas and Catherine Zeta-Jones (25 years)

Whispers of infidelity trailed Michael Douglas, even though his first marriage lasted more than 20 years. At 56, he married a 31-year-old Catherine Zeta-Jones. They now have two children together and will celebrate their fifth anniversary in November.

Interestingly, though many people express shock over the couple's age difference, Douglas' next leading lady will be even younger than his wife. He is set to star with 31-year-old Bollywood superstar Aishwarya Rai in "Racing the Monsoon," due out next year.

8. Rod Stewart and Rachel Hunter (25 Years)

How long can you reasonably expect to stay married to a man whose mantra is "Forever Young"?

Earlier this month, Rod Stewart announced that Penny Lancaster, his 34-year-old fiancée, is pregnant with the 60-year-old's seventh child.

The Grammy-winning singer only forgot one thing — he isn't yet divorced from his last wife, Rachel Hunter, the 35-year-old mother to two of his children. The couple separated in 1999, but the divorce proceedings were subsequently dropped.

It's amazing how time flies for rock stars. In 1967, a 25-year-old Paul McCartney was singing, "Will you still need me, will you still feed me, when I'm 64?"

These days, the 63-year-old Sir Paul and his 37-year-old wife are caring for their 1-year-old daughter.

9: Liz Taylor and Larry Fortensky (20 Years)

All you really need to know about Elizabeth Taylor's eighth marriage is that it took place in 1991 at Michael Jackson's Neverland ranch, with the "King of Pop" serving as best man.

Taylor was 59 when she met her groom, 39-year-old construction worker Larry Fortensky, when they were in rehab together at the Betty Ford Clinic.

Fortensky hadn't been born when an 18-year-old Taylor married her first husband, hotel heir Conrad Hilton Jr. While that marriage lasted only 205 days, Fortensky managed to make it five years with Liz, which is more than Eddie Fisher and some of her other husbands can say.

Taylor has always been criticized as a serial bride. But after her ill-fated romance with Fortensky, she's managed to keep one vow — promising never to marry again.

Buck Wolf is entertainment producer at ABCNEWS.com. "The Wolf Files" is published Tuesdays.