A very special contribution from our friends at Mr. Skin.

Twenty-five summers ago, the PG-rated blockbusters "Gremlins" and "Indiana Jones and the Temple of Doom" proved to be so violent and scary that parents demanded a new movie rating. At issue were films that were not quite "E.T."-level family friendly, but also not really deserving of the R-rating that went to "Bachelor Party" or "Purple Rain."

In response, the Motion Picture Association of America (MPAA) concocted the PG-13, which "strongly cautioned" parents if they were considering allowing tykes under age 13 to see a film bearing the new rating. The first Hollywood film to carry the PG-13 imprimatur was "Red Dawn," which hit theaters on August 10, ablaze with combat action and explosive mayhem, but no nudity. Five days later, funnyman Gene Wilder's "The Woman in Red" (pictured) opened, and took full-frontal naked advantage of its PG-13.

Since then, PG-13 nudity has been rare, but when it happens, it's often done well. After the jump, check out a countdown of 13 examples of such heady moments, while considering yourself "strongly cautioned."

Kelly LeBrock
"The Woman in Red" (1984)
Bare-breasted Kelly beds Gene Wilder, then hops up from the sheets and gives us a peek at her fully bottomless beauty. She is not wearing red. Or anything else! (1:14)

Anna Faris
"The House Bunny" (2008)
Ex-centerfold Anna nakedly addresses some shocked sorority girls, enabling us to savor her sweet seat in the process. Bunny Anna boasts quite a tail. (0:22)

Kate Winslet
"Titanic" (1997)
Kate proves that her sex appeal is as epic as the biggest blockbuster of all time when she poses in the buff for artist Leonardo DiCaprio. That body is unsinkable! (1:25)

Joyce Hyser
"Just One of the Guys" (1985)
The greatest of all gender-bending teen comedies climaxes with Joyce, who's pretended to be a dude all semester, popping open her prom tux to reveal that she's two full D-cups of woman. (1:28)

Catherine Bell
"Death Becomes Her" (1992)
Normally, we don't honor the work of a Body Double, but here, JAG's Catherine Bell climbs out of a pool and steps in for Isabella Rosselini's character, exposing her utterly becoming backside and bouncing side-boob. (1:20)

Angelina Jolie
"Hackers" (1995)
The flesh-flash is quick, but it's the flesh of 19-year-old Angelina Jolie, which brings world-class heft to a brief shot of her front-bumpers as she struts about in an open jacket.
Moira Kelly
"Chaplin" (1992)
What a Little Tramp! No, not Moira -- that's what fans called silent-film legend Charlie Chaplin. Moira portrays one of the star's young brides, and her naked knockers will flip your bowler hat. (0:21)

Lauren Holly
"Dumb & Dumber" (1994)
Jim Carrey plays stupid while embracing Lauren and lifting her skirt to cracklingly reveal that she's not wearing panties. What a smartass! (0:31)

Evan Rachel Wood
"Across the Universe" (2007)
The Beatles musical hits a high note as Evan Rachel rouses from slumber on a couch and exposes her left Sgt. Nipper. You'll get high with a little help from this friend. (1:17)

Milla Jovovich
"The Fifth Element" (1997)
Milla embodies "the perfect being" in this sci-fi favorite, snoozing shirtless in an oxygen chamber while displaying the succulent features that have earned her the nickname G.N.A.T.s -- Greatest Nipples of All Time. (0:27)

Amber Heard
"Friday Night Lights" (2004)
Before her intoxicating turn as Seth Rogen's teen girlfriend in Pineapple Express (2008), Amber scored big in this football saga, flashing boobage in bed with the quarterback during the play of his life. (0:18)

Rachel McAdams
"The Notebook" (2004)
Two scoops of Rachel's sweet rack during a heavy-breathing love scene help this chick flick go down, in the most delightful way. (1:21)

Charlize Theron
"The Cider House Rules" (1999)
Charlize sprawls bare on a bed, roundly pointing her perfect posterior right at the camera, then flips to expose a hint of right nipping. (0:15)

From the Web:

2012 Orgy
Time to bone like there's no tomorrow. (CollegeHumor)
Who Has the Biggest Boobs in the World?
The answer may surprise you. NSFW (Gorilla Mask)
Zombie Hooker Nightmare!
2! (Adult Swim)