What started as just a spread of women in bathing suits to fill space during a time of year with little sports news has turned into a seminal beachwear fashion issue that has launched the careers of several of the world's top supermodels. And this year, the most anticipated annual magazine issue is going 3-D. See our list of the hottest Sports Illustrated swimsuit cover girls.
Brooklyn Decker's 2010 SI coverThen: This fashion model showed off a swim collection last year and is married to a top-ranked tennis player
Now: She made a very personal admission in a recent interview. The beauty is starring in a funny new film
Christie Brinkley's 1979 SI coverThen: This cover girl spent three consecutive years on the cover of the Sports Illustrated swimsuit issue. The "Uptown Girl" also appeared in her rocking then-husband's music video
Now: Today the former supermodel is reportedly worth millions. She appeared in a now-canceled TV show
Rachel Hunter's 1994 SI coverThen: This model married a raspy-voiced singing legend, but they divorced in 2006. She got her acting start on a comedy about a regular guy living in Cleveland and played a hot mom in a music video.
Now: Hunter showed off her moves on a reality competition and hosted a fashion challenge program.
Cheryl Tiegs' 1979 SI coverThen: By the time this Minnesota native was 17 she had already appeared on the cover of a major fashion magazine, but it was the 1978 image of her in a pink bikini that made her an icon.
Now: The former supermodel has since appeared on a reality show that measured contestants' inner beauty and developed her own accessory and wig line for Revlon.
Petra Nemcova's 2003 SI coverThen: The Czech model founded a nonprofit organization that aims to improve children's lives. She was injured in a major natural disaster and her fiancé was killed.
Now: After recovering from the tragedy, the supermodel is now engaged to an English actor. She featured prominently in a music video by an indie rock group
Elle Macpherson's 1986 SI coverThen: The Australian supermodel with a fitting nickname made the Sports Illustrated swimsuit cover a record number of times.
Now: All her hard work must have paid off because she's now the host of a spin-off reality series and reportedly enjoys a hefty bank account.
Tyra Banks' 1997 SI coverThen: This model-turned-actress was the first African-American woman on the cover of the iconic issue, not to mention a high-end men's fashion magazine. She got her start on TV with a role on a sitcom about a street-smart teen living in Bel-Air.
Now: She's a top model on her own reality show and recently ended a daytime talk show.
Rebecca Romijn's 1999 SI coverThen: This model-actress married and divorced Uncle Jesse and famously donned head-to-toe body paint as a shape-shifter in a comic-book franchise film series.
Now: She recently wed a former child star and played a scheming fashion executive on a now-canceled TV show.
Heidi Klum's 1998 SI coverThen: After this German model appeared on the cover of a fashion bible and her first Sports Illustrated swimsuit issue hit the newsstands, she became widely known as one of the top supermodels.
Now: Klum cultivated a business empire as a successful TV host and was named one of the world's top-earning supermodels. The former Victoria's Secret model married a famous musician. Check out the cute photos of their kids.
Bar Refaeli's 2009 SI coverThen: She was the first Israeli model to appear in Sports Illustrated but caused controversy when an image from the cover shoot was painted on the side of a plane.
Now: The Jewish model is perhaps best known for her on-again, off-again relationship with an Academy Award-nominated actor. She sizzles in a new lingerie ad campaign.
Beyoncé Knowles' 2007 SI coverThen: This Grammy-winning "Dreamgirl" graced the cover of a music-themed Sports Illustrated in a bikini from a fashion label she started. When this "King of Hip-Hop" put a ring on it, the singer was solidified a member of one of Hollywood's elite power couples.
Now: The diva hopes her new scent will have women feeling "sensual". A famed director has just signed on to direct the singer-actress in a remake of a 1976 film.