After three years of Emma, it's Sophia's turn at the top of the class roster, joining Aiden for his third stint.

A growing Hispanic population might be credited for some name climbers on BabyCenter.com's list of most popular baby names for 2007. Sophia has more of a Latin or continental appeal than its proper English successor, Emma. Xavier, Sebastian and Isabella are on the rise, while newcomers to the top 100, to be released next month, include Lila, Maria and Adrien.

"It might be representing the changing face of America," said Linda Murray, editor-in-chief of the BabyCenter Web site.

But if anything sums up the Web site's latest hit names, it's a hunt for distinctiveness -- a trend that has rendered the annual list way more volatile in recent years than 10 or 20 years ago, when Michael could sit securely on his throne for decades.

Experts have seen an influx of untraditional names and alternate spellings; "unique" has become conventional.

Venturing even further into the written wild is a nascent creative use of the apostrophe. Despite a population so often bewildered by the difference between "its and it's," some parents have used apostrophes and mid-word capitalization to transform Jayden, Cameron and Devon, for example, into Jay'Den, Cam'Ron and De'Von, BabyCenter's Murray said.

Unlike the Social Security Administration's annual rundown, which comes out in May, BabyCenter categorizes names by sound instead of spelling, and compiles its list from the 300,000 new births voluntarily registered on their site this year. The Social Security list is more comprehensive -- surveying millions of new card holders -- but can underemphasize the popularity of names like McKenzie that are spelled in several ways.

Last year, Social Security ranked Emily and Jacob as its top names.

Fairly common Adam and Robert fell 16 and 15 spots respectively last year, while Jayden plowed his way from 19 to 4 despite its association with the son of fallen idol -- and poster child for bad parenting -- Britney Spears.

Moms and dads are increasingly influenced by celebrities, said Pamela Redmond Satran, co-author of 'The Baby Name Bible.'

"So many have names that are really distinctive, and they're giving their kids names that are unique," she said. "You get the message that having a singular name makes you a singular person."

Now, once-favored Michael sits at 13th place, and the leading boy's name -- Aiden -- brings to mind a beloved boyfriend character on "Sex and the City."

An informal survey of new parents active on BabyCenter community boards reveals several names inspired by television shows: Miranda ("Sex and the City,") Colton ("The Real Housewives of Orange County,") Dexter ("Dexter,") and Gideon ("Criminal Minds."")

Names that become very strongly associated with one particular celebrity, however, tend to fall out of the running quickly, Murray said. Angelina fell off the top 100 list this year, presumably unable to compete with Angelina Jolie for ownership.

Satran said parents give prospective names tests. They ask: "‘Is this name going to get him into Yale?' ... ‘Does this sound like a kid who can catch a ball?' ... 'Is this a name that's going to get invited out on a date or invited to a party?'"