The year was... well, we are informed only that it was sometime in the "mid-'70s."

A man named Gary Dahl was spending a heady night in a Northern California bar. The drinkers' talk turned to pets, and Dahl, a freelance copywriter ("that's another word for broke," he later quipped) shared that he had taken in the easiest, best pet of all time.

He had found a pet that didn't need to be fed, never needed to be walked, never needed to be cleaned up after: a rock.

With such a feat of "bibulous inspiration," as the New York Times described it, Dahl, who died recently at the age of 78, came up with what would become an icon of the decade. As Inc. put it in 1994:

The fad broke in October 1975 and was dead as a stone the next February, giving Dahl an Andy Warhol-like five months in the spotlight. He had to give away tens of thousands of unsold Pet Rocks.

Yet, for a few months, for $3.95 (about $17.87 today), you could be the proud owner of a "smooth Mexican beach stone," accompanied by 36 pages of careful instructions, according to the Times.

The genius was in the packaging. Each Pet Rock came in a cardboard carrying case, complete with air holes, tenderly nestled on a bed of excelsior. Mr. Dahl's droll masterstroke was his accompanying manual on the care, feeding and house training of Pet Rocks.

"If, when you remove the rock from its box it appears to be excited, place it on some old newspapers," the manual read. "The rock will know what the paper is for and will require no further instruction. It will remain on the paper until you remove it."

Pet Rocks hit the marketplace in time for Christmas 1975. They were soon featured on The Tonight Show and in a blizzard of newspaper articles. In a matter of months, some 1.5 million rocks were sold.

Dahl became a millionaire almost overnight, and although his star faded within months and he wound up mired in litigation with his investors, his entrepreneurial exploits weren't quite finished. He later launched an "Original Sand Breeding Kit," along with "Red China Dirt," which was described as "a plan to smuggle mainland China into the United States, one cubic centimeter at a time." He even wrote the book, Advertising for Dummies.

But he never achieved the same level of success as he had with the Pet Rock. As the Times summarized:

Though the rock made him wealthy, it also made him wary, for he was besieged ever after by hordes of would-be inventors, seeking his advice on the next big thing.

"There's a bizarre lunatic fringe who feel I owe them a living," Mr. Dahl told The Associated Press in 1988. "Sometimes I look back and wonder if my life wouldn't have been simpler if I hadn't done it."

So, rest in peace Mr. Dahl. And for the rest of us, think about this rock star entrepreneur of rocks the next time you're wondering if you have it in you to launch a business, to found a new venture, and to pursue your dreams. Perhaps you can't squeeze blood from a stone--but at least one man showed how to turn it into money.