Celebrity Style: Coming to a Department Store Near You

Gwen Stefani, Jennifer Lopez, Sean "Diddy" Combs -- what do they have in common? Yes, they are all singers, but they all also have their own clothing lines.

These days it is easier than ever to adapt celeb style into your own wardrobe. Celebrities are expressing their creativity -- and good business sense -- in many ways.

"I love doing it, Stefani said. "It all comes from the same place whether its music or designing. It all comes the same place for me."

Stefani recently joined the likes of Kimora Lee Simmons (husband of producer Russell Simmons) and Jay-Z to further brand her image. Her new line of clothes L.A.M.B. -- which stands for loving angel music baby -- is expected to gross $40 million this year -- peanuts compared to what Diddy rakes in with his line Sean Jean. He grosses more than $400 million and his ex-girlfriend, Jennifer Lopez, brings in about $300 million with her Sweetface and J-Lo lines.

Some experts say that the outbreak of celebrity fashion lines is a symptom of a celebrity-crazed culture.

"I think the majority of the customers who are buying into the celebrity label right now are really customers who are celebrity-obsessed," said Jamie Ross of the Doneger Group, a consulting group for retailers. "If they identitify with that particular celebrity they can kind of pick up their style and relate to that as opposed to having to make a lot of decisions themselves."

One of the first celebrity fashion designers was original "Charlie's Angel" Jaclyn Smith.

Her line, which is sold at Kmart, brings in $300 million annually and she has been at it for 20 years.

"We reach a diverse group of women," Smith said. "It's not just a size 6 or 16. Part of our success is that we've kept the quality and the styling and the value is there."

Smith says she does not mind the competition, but questions the intentions of some of her peers. For example: childless Jessica Alba is designg baby clothes; the Olsen twins are adding boys' clothes to their line; and Miss Daisy Duke herself, Jessica Simpson, is making plus-size jeans.

Smith's longevity in the fashion world is rare. Most celebrity lines last only two years.

"They have to stay on top of the design and the fit," Ross said. "If they are just a name to the brand that's not good enough any more. They really have to be more heavily involved in the line."