JAMES & OLIVER PHELPS

• As Harry Potter's Fred and George Weasley, they're a matched set of flame-haired mischief. But away from Hogwarts, James and Oliver Phelps, 20, aren't redheads—or even, they say, very much alike.

James (left): We've learned to watch each other's backs, but we're pretty different personalities. I tend to take the mickey to tease a bit more, while Oliver is more sensitive.

Oliver: Stylewise, what I think is good James thinks isn't. When we're finished filming [Harry Potter and the Order of the Phoenix], I'm going to let my hair grow in dark brown with highlights. James wants his short.

James: We'll be brown again when we get clearance from the studio.

Oliver: Probably around Christmastime. In time for the family photos.

SHAWN & AARON ASHMORE

• X-Men's Shawn and Smallville's Aaron, 27, are close enough to have a sort of ESP but secure enough for some healthy competition.

Shawn (top): We know each other so well that I know exactly how he's going to answer a question. One of our friends says that we have this whole language of looks and subtle things. We have an unspoken language.

Aaron: We don't butt into each other's sentences as much anymore. I think we matured and realized it was rude.

Shawn: Whenever we meet each other's girlfriends, we send signals to each other if she is a cool girl or not.

Aaron: We like the same type of girls, but it's never been an issue.

Shawn: We both go after her and see who she wants.

Aaron: The girls usually settle it for us.

TIKI & RONDE BARBER

• Though the 31-year-olds play on different teams in the NFL, Tiki, running back for the New York Giants, and Ronde, cornerback for the Tampa Bay Buccaneers, are just as close as ever, penning their third children's book, Teammates, together and sharing style secrets.

Tiki (left): Ronde's older by seven minutes. But Tiki is wiser by ...

Ronde: leaps and bounds! Tiki has taught me how to dress. I've picked up an attention to details from him.

Tiki: Like pocket squares.

Ronde: And how to correctly tie a tie.

Tiki: Ronde is more of a casual, shirt-unbuttoned-halfway-down his-chest, edgy sexy.

Ronde: Whatever.

Tiki: Dude, you are! I find myself sexy by putting on a suit.

Ronde: I'm casual sexy. Tiki's more sophisticated sexy.

Tiki: Ronde would rather see a woman in a bathing suit, where I'd prefer an evening gown. That's the difference between casual and sophisticated sexy!

BOB & MIKE BRYAN

• At 28, they're tennis's top-ranked doubles team. Here, they volley back and forth about love.

Bob (left): Mike has a serious girlfriend right now, and I'm single and dating.

Mike: You'll have a girlfriend in no time, though.

Bob: I don't really have a certain "type." They don't have to be athletic. I've dated girls who don't even know how to keep score in tennis, but it helps if she understands our lifestyle.

Mike: I've dated girls of a lot of different nationalities and a lot of girls with curly hair. I really seem to like curly hair.

Bob: You go for blondes.

Mike: Dude, I've dated everything. But we've never dated twins.

Bob: That would be fun.

BENJI & JOEL MADDEN

• Both members of the band Good Charlotte, the 27-year-olds are neighbors—and their girl-friends have to accept that the two of them are a package deal.

Joel (right): We dream together, we work together, we do everything together. It's a 50-50 split.

Benji: Things don't happen without each other. I know that both of us could write a song on our own, but it's not going to be as good as if we write it together.

Joel: We're an old married couple.

Benji: We're as close as two people could get.

Joel: It takes a special kind of girl to accept the three. When you're dating me, you have to take Benj into the trust tree.

Benji: Hilary [Duff, Joel's girlfriend] is like my sister.

Joel: Benj and my girlfriend are very similar.

Benji: Because we both take care of you?

Joel: You're attracted to the things you need.