What are the criteria that raise an entertainment superstar to legend status? The biographical movies made and books written about them? The awards and honors bestowed upon them? The Hollywood Boulevard trinkets in their likeness? All of the above?

Back in 1964, a U.S. Supreme Court Justice famously declared that he could not define pornography, "but I know it when I see it."

Elvis is the ultimate proof that the same phrase can also apply to show business legends. Often, the status of "legend" is cemented in the public's mind after a star's death. The fact is, however, that Hollywood has a number of this rarest of all breeds right here, right now, whose lives and work in and out of movies have already made an exceptional lasting mark.

The American Film Institute knows a thing or two about what becomes a legend most - as can be seen in the list of the esteemed body's Lifetime Achievement Award winners. To name a few:

George Lucas 2005, Meryl Streep 2004, Robert De Niro 2003, Tom Hanks 2002, Barbra Streisand 2001, Harrison Ford 2000, Dustin Hoffman 1999, Robert Wise 1998, Martin Scorsese 1997, Clint Eastwood 1996, Steven Spielberg 1995, Jack Nicholson 1994, Elizabeth Taylor 1993, Sidney Poitier 1992, Kirk Douglas 1991.

On the other hand, it doesn't take an AFI tribute (which require the honoree to be present for the televised ceremony) to make a legend.

Paul Newman and Robert Redford most certainly qualify as legends. When it comes to those Hollywood Boulevard trinkets, they're usually immortalized in their "Butch Cassidy & the Sundance Kid" roles. They've not only achieved the highest accolades for their respective amazing bodies of film work, but made the world better with philanthropic enterprises that have helped countless sick children, in the case of Newman -- and in Redford's case, with the establishment of perhaps the most influential breeding ground for independent filmmakers in the world.

Shirley Temple, still moving merchandise - including DVDs of her movies for another new generation -- as the most beloved child star in history, she's wrapping up work on the second part of her autobiography, covering her adult life as a leading American diplomat. Legendary? No question.

Washington's Kennedy Center Honors are another place to find people in the entertainment world who may merit legend status. In the past five years, those have included: Warren Beatty, Ossie Davis & Ruby Dee, Elton John, James Brown, Carol Burnett, Loretta Lynn, James Earl Jones, Elizabeth Taylor, Julie Andrews, Quincy Jones, Jack Nicholson, Angela Lansbury, Chuck Berry and Clint Eastwood.

You can be controversial (Jane Fonda, Michael Jackson) and still be a legend.

The formerly controversial Charleton Heston's star has sadly dimmed as he's slipped into Alzheimer's, but you can find his strong young likeness out there among those Hollywood Boulevard tchotchkes due to his immortal "Ben Hur" chariot race. The actor, whose political activism ranged from liberal (the 1960s Civil Rights Movement) to conservative (the NRA) won't be forgotten. When the time comes, the posthumous tributes will be prolific.