Twins!

Though greatly overshadowed by the trendy Olivia, Olive has a quiet, subtle appeal of its own -- and is now enjoying a remarkable comeback. Olive is one of only four girl names starting with O on the US Top 1000. Cool couple Isla Fisher and Sacha Baron Cohen chose it for their daughter, reviving the name to stylishness, and now Drew Barrymore has a little Olive too, as has country singer Jake Owen.

Olivia, a lovely Shakespearean name with an admirable balance of strength and femininity, is the Number 1 name for baby girls in the US and one of the top girls' names around the world.

Oriana is a dashing medieval name, with a meaning similar to Aurora. At this point, though, Oriana is much more unusual than Aurora and makes a unique choice if you're searching for names that mean new beginnings or dawn.

This slightly more compact version of Sabina has ties to France and Germany. Unlike its sister name, Sabine has never charted in the United States Top 1000. Today, both names are given to roughly the same number of baby girls in the US, about 70 each year.

Sadie started as a nickname for Sarah, but their images couldn't be more disparate. Where Sarah is serious and sweet, Sadie is full of sass and fun.

Sawyer is one of the top unisex names, used for their daughters by such parents as Sara Gilbert, co-host of The Talk and former actress on Roseanne, currently on The Conners.

Scarlett Johansson is doing more for this sparky southern name than Scarlett O'Hara ever did. Since the turn of the 21st century, Scarlett has gone from an obscure literary name to one of the most popular girls' names starting with S, right after longtime favorites Sophia and Sofia.

Scout, a character nickname from To Kill a Mockingbird (her real name was Jean Louise), became a real-life possibility when Bruce Willis and Demi Moore used it for their now-grown middle daughter, followed by Tom Berenger a few years later. A unisex choice that is growing in popularity for both genders—but given to girls about four times more often than to boys—it was picked by skater Tai Babilonia for her son and Kerri Walsh for her daughter Scout Margery.

Serena, a name used since Roman times, was given fresh life by tennis star Williams, and then again with the leading character on Gossip Girl, Serena van der Woodsen. There have also been Serenas on soap operas and other shows from Bewitched to Law & Order.