Some 30 phrases for testicles - "satchel full of yarbles," "donkey omelets" and "nutty buddies" to name a few - in a sing-a-long viral video that's a current hit on YouTube.

The Salt Lake City-based ad agency Struck and production house Cosmic Pictures created and produced a campaign they call "Carpe Testes" - humorously translated as "seize the balls" - for a New York testicular cancer foundation. Six months after their five videos were posted online, the sing-a-long, purposefully set to the tune "Do Your Ears Hang Low," was featured on YouTube's home page this week.

As of Friday morning, it was approaching 980,000 views.

"Some people may look at it and think they're off color," said Mark Rawlins, associate creative director with Struck who co-wrote the song. "But [the videos] get people talking about it. That is really our goal, [to] reach a demographic, a younger male demographic, that needs to really consider the risks of the disease."

The ads were designed pro bono, or for free, for the Sean Kimerling Testicular Cancer Foundation, which promotes regular self exams. It says testicular cancer is the most common cancer among men between ages 15 and 40 and has a high cure rate if found and treated early.

Sean Kimerling, who died at age 37, didn't realize he had cancer until he had severe back pain, a symptom of later-stage cancer. He was an Emmy award winning sportscaster and pre-game announcer for the New York Mets.

While some viewers posted comments saying testicular cancer is no laughing matter, many wrote in to say they liked the video.

"Important message to all guys," wrote WhitlockSam. "It makes it stick with humor. If only they could make organic chemistry this cool to learn."

The one minute sing-a-long - the bouncing ball tracking the lyrics are actually two balls - is set on a farm. Utah actor Adam Johnson, wearing overalls, plays a guitar while two bales of hay roll down a hill and a testes-endowed hummingbird flies by, along with a cupid carrying two cherries.

"If your balls are feeling lumpy

"If they're tender or they're grumpy

"If you notice you got three than a doctor you should see

"If they're swelling up your pants, don't miss your chance

"Go see a physician."

Other videos in the campaign show a man dressed as a testicle skating in an ice rink getting "checked" by a hockey player.

Another called "Jewels" shows a man in a bank handling two blue, golf-ball-sized gems. And one more is styled as an old fashioned news reel with a doctor advising men to examine themselves. "If mother asks why you're constantly handling your love apples, tell her Dr. Rounds gave you a lifetime prescription to do so."

Some "awkward Google searches" provided the lyrical inspiration, Rawlins said.

"I love the fact this kind of campaign came out of a small shop in Salt Lake," added Nick Driggs, a Struck writer and editor. "It was just so much fun. There's no end to the references."