However, Americans tend to prefer those names that are already in common usage. 

"Since man first began walking the earth, each individual has had a distinctive name. Creating a totally original name for a child is traditional in many cultures; however in the American culture the normal practice is to choose a pre-existing name," said Shelly Clark, a researcher of regional baby names. 

The desire to repeat names triggered the Jenny-ration and Web sites like The Society For Preventing Parents From Naming Their Children Jennifer. 

SPPNTCJ even jokes on its site that there are enough Jennifers to populate their own country. 

There are greater concerns caused by such naming en masse, though. 

Jenn Farwell, co-creator of the Web site Jen Central, said she believes there are possible effects to being a Jennifer. 

"In school, constantly being known by a last initial. The feeling of not having your own identity. The fear of telling people your name, knowing the response, 'Another Jennifer?' is coming," she said. 

Such concerns have made the SPPNTCJ more than 500 members strong. 

Jen Hammond, who also created Jen Central, said she thinks this phenomenon could happen again. 

"It doesn't take long for a fad to take hold. All it takes is many people admiring someone with a name and then you have a million people running around with the same name," she said. 

The recent trend towards unique names may provide a break before any new name phenomenon. 

Proof of the trend is in the businesses like the Anagram Name Service, where people can discover all the name aliases available within a series of words by rearranging the letters. 

Web sites like Babynamer.com also offer name information to help select a special name for a baby. 

These options provide ample ways for name popularity to dwindle and to prevent any further Jenny-rations.