Hilariously parodied in The Jerk, when Steve Martin leaps from the bathtub and goes charging outside naked but covering his groin with his small pet dog. Once outside, he picks up another small dog to cover his backside.
During A Fish Called Wanda, Archie uses a vacant apartment to seduce Wanda. However new tenants arrive during his nude dance, so he fumbles to retrieve the closest object to cover his privates. Unfortunately, it turns out to be a portrait of the apartment's owner.
In Rush Hour 2, Inspector Lee and James Carter end up running through the streets of Hong Kong completely naked after a fight at a massage parlor. A short time later, Carter is using two garbage can lids to cover himself and Lee is using two old newspapers to do the same.
In the underrated musical movie The American Mall, during the "The New You" song, two of Madison's back-up dancers rip off Joey's clothing and he covers his groin with his hands... even thought he was already in his boxers.
The... er... climax of The Full Monty shows the men use the caps of their policeman stripper outfits to cover their naughty bits before tossing them away to general cheering.
Inadvertedly funnily done in Friday the 13th Part 2. Terry gets out of the water from Skinny Dipping, and finds her clothing missing. She then covers up her chest calling out to the guy who stole them. Funny in that she does not cover her groin (which was out of frame).
Likewise, during the first death scene from the original Halloween 1978, Michael's sister covers her breasts with her hands as she's being killed. Apparently, keeping her nipples from showing up on camera is more important than either hiding her groin or fending off a knife attack.
She reflexively covers her breasts when she sees her little brother in the room to avoid exposing herself to him (in the split second before he begins attacking her), then continues to keep them there in a futile attempt to defend herself.
In Bedknobs And Broomsticks, the Secretary Bird does this after his clothing (minus his necktie) gets blown off of him by King Ledonias' yelling. Though, he didn't really have anything to cover up in the first place...
A Shot in the Dark invokes the trope when Inspector Clouseau visits a nudist colony to question a suspect. He borrows a guitar just so he can hold it front of himself, and has a pool float on his back.
In The Proposal, Sandra Bullock goes after a towel, fighting the dog, with only her arms to cover herself.
In Fantastic Four, the first time Johnny Storm flames on, he vaporizes all of his clothing and spends a considerable amount of time awkwardly prancing around naked with his ski instructor's jacket around his waist (after doing her of course).
In Carry On Dick, Dick Turpin (Sid James) robs the clothing off the Police Inspector (Kenneth Williams) and his wife. She has only her big hat in front of her.
In Airheads, Pip (Adam Sandler) uses his cap when he's caught making out with station employee Suzzi.
In the first part of the film version of Till Death Us Do Part (set during the Second World War), Alf Garnett is having a bath in front of the fire when the National Anthem is played on the radio. Being a patriotic Englishman, he stands up — then realises he's facing a photograph of the King and Queen which is hanging on the wall. He's forced to cover his groin with his hands until the anthem finishes.
At the end of Journey to the Center of the Earth (1959) Pat Boone ends up a tree completely naked, trying to hide his body from a group of Italian nuns. After being suddenly deposited on the ground, he grabs a sheep and runs off clutching it to his groin. Insert joke here....
Danielle De Luca does this in Naked Fear when she initially wakes up naked and a little while after when she's walking around looking for someone, despite being in the middle of the wilderness and having no one around for miles.
The first Austin Powers movie parodies this trope with an intricately choreographed scene on Austin and Vanessa's wedding night. Both are walking around naked while Austin talks to Basil on the videophone. His package is covered up by, variously, a wrapped gift box, his phone, and a balloon; her chest gets a pair of pineapples, a pair of melons, a pair of cream pitchers, and a drawing of a woman's breasts.
In American Reunion, a pantless Jim covers himself with the lid of a pan, however we learn later that the lid is made of glass and transparent. There is an up-close shot before he gets a frying pan to replace it.