The dance floor at Smokey Joe's is packed on a recent Saturday night when the song comes on.

"YOOOOOOUUUUU!"

As soon as the crowd recognizes it, hoots and squeals rise throughout the bar.

"Ayy, I got this new dance fo y'all called the Soulja Boy. You gotta punch den crank back three times from left to right."

Suddenly, the dance floor is overtaken with strangers dancing in unison.

As the song, "Crank Dat (Soulja Boy)" by 17-year-old rapper Soulja Boy, continues to top the Billboard charts, the accompanying dance is booming in popularity across the country - and Penn is no exception.

"It's like the electric slide," College sophomore Ted Kreider said. "If it comes on at a party, you want to learn how to 'crank that.'"

And thanks to an official instructional video on YouTube, which has been viewed more than 13.5 million times, the dance is becoming increasingly recognized and replicated - even among people who don't like the track.

College sophomore Cameron Clark loves the dance and has taught it to a couple dozen friends, but he still calls it "one of the worst songs ever made."

"Everyone knows 'Soulja Boy.' Everyone. And if they don't know it, they know parts of it," said College sophomore Alix Pruzansky, who picked up the moves from the online video. "I'd say it's spreading like wildfire."

And she's helping to spread it. Pruzansky said she recently taught a group of people the moves at the Rena Rowan 5K Ribbon Run, a breast-cancer-awareness run. She even considered a Soulja Boy Halloween costume, but she figured that the artist's sunglasses - which have "SOULJA BOY" scribbled across the lenses - might be too dangerous to wear in the dark.

College sophomore E.J. Baker may have upstaged her: Baker helped teach the dance to an entire summer camp in Rochester, NY.

"All the kids loved it," Baker said, "It became the most popular song of the summer."

For a while, Baker and her fellow camp counselors would play it at least three times a day.

"The kids were starting to sing along to it," Baker said. "I still don't think they exactly knew what it meant, but when you have eight-year-olds singing 'Superman that ho,' maybe it's time to phase it out."

Her campers aren't the only youngsters who know the dance - YouTube is littered with videos of people of all ages, races and places moving to their own variation of the hit.

"'Soulja Boy' is just another one of these dances that makes everyone feel like they're part of the scene, part of the fad, part of the trend," said Northeastern University professor Emmett Price, who teaches a class on hip-hop culture.

As for the vulgarity of the song, which has lyrics like "super-soak that ho," most students say they don't think about it.

"Young people have a tendency to listen to the beat and not the words," Price explained. Even if the lyrics are crude or misogynistic, people don't associate the words with themselves, he added.

So what makes Soulja Boy such a phenomenon? The right timing and the right marketing, Price said.

In the meantime, students are unsure if Soulja Boy has the potential to reach Electric Slide- and Macarena-type proportions.

"If I start hearing it at Bar Mitzvahs," Baker said, "then it has reached that point."