Lemondrop

If you've ever been in a high school play, then you know why there are so many celebrities who forge their friendships on the set. There's the obvious case of forever "Friends" Courteney Cox and Jennifer Aniston, not to mention "Bandidas" Penelope Cruz and Salma Hayek, who, we assume, mostly bond over being absurdly hot Latinas with perfect hair.

When we read recently that Emily Blunt and Amy Adams are best friends, we were pleasantly surprised -- that is a pinot-grigio-and-silly-movie night we would love to be invited to. We wondered what other celeb pal couplings we didn't know about, so we dug around a little. From "Twilight" co-stars to pop-star soul mates, here are some surprise celeb she-bros we found.

Emily Blunt and Amy Adams
Where They Likely Met: Oh yeeeeah! They co-starred as sisters in a little indie flick called "Sunshine Cleaning."
Seen Together: Doing shots of Patron while tucking Benjamins into dancers' G-strings at Chippendales? No, not really, just out dancing and sipping cocktails for Blunt's "hen party" (that's English for bachelorette party).
Why They're Friends: They have similar taste in critically lauded film roles ... and men. Amy used to date Em's fiance, the dreamy John Krasinski ... on-screen, that is, during early seasons of "The Office."

Nikki Reed and Kristen Stewart
Where They Likely Met: At a teen vampire and significant-others-of-vampires convention.
Seen Together: Signing autographs for "New Moon: Eclipse," vacationing in Africa together and walking around L.A. holding hands. (Cue Twihard Twitter feeds imploding.)
Why They're Friends: They both, like, have so much angst.

Jillian Michaels and Vanessa Marcil
Where They Likely Met: At some trendy L.A. gym.
Seen Together: Working out, clubbin', hanging with Vanessa's 8-year-old son, Kassius, who calls Jillian his godmother ... and Megan Fox his stepmom.
Why They're Friends: Both enjoy stirring up drama -- Jillian by yelling at participants of reality TV shows, "Losing It With Jillian" and "The Biggest Loser" and Vanessa by playing the mixed-up bad girl on soap operas like "General Hospital" and "Beverly Hills, 90210."

Katy Perry and Rihanna
Where They Likely Met: Backstage at the MTV Video Awards, scrutinizing one another's Gaga-esque couture.
Seen Together: On vacation in RiRi's homeland of Barbados, boating and sunbathing. Next up: Katy recently revealed that she would like Rihanna to strip at her bachelorette party.
Why They're Friends: They share a love of pop-chart climbing, tattoos and rude boys.
Jessica Biel and Jennifer Garner
Where They Likely Met: On the set of the 2010 rom-com bomb, "Valentine's Day."
Seen Together: Leaving loverboys Ben Affleck and Justin Timberlake at home for a girls' night out. The duo dined on fine Italian food in West Hollywood.
Why They're Friends: They're both down-to-earth Midwestern girls (Biel's originally from Minnesota, Garner from West Virginia) who have a rep for being ripped action heroines. But now, friends say these funny gals are the new millennium's answer to the 1970s sitcom "Laverne & Shirley."

Rashida Jones and Natalie Portman
Where They Likely Met: Could have been a Harvard alumnae function. Both Ivy League gals, the two are now running neck and neck to be named Hollywood's number one Brainiac Bombshell.
Seen Together: Performing goofy/political sketch comedy on Funny or Die.
Why They're Friends: They both love puppies! And kitties! Don't forget ... chickens!

Kimora Lee Simmons and Tyra Banks
Where They Likely Met: 1989. Paris. Backstage at Oscar de La Renta. Both had a penchant for side ponies and shoulder pads.
Seen Together: In addition to from fashion, the two have an eye for basketball. They've been spotted together courtside at New York Knicks games. Also, Tyra was a bridesmaid at Kimora's wedding to Russell Simmons.
Why They're Friends: They're both incredibly successful fashionista businesswomen who started in the modeling biz. And they're also 100 times more fabulous than you and we are.

Sandra Bullock and Betty White
Where They Likely Met: Betty played Sandra's mischievous grandma in the 2009 funny flick, "The Proposal."
Seen Together: On the awards-show circuit.
Why They're Friends: They're America's sweethearts of the moment. Both have a nation of devoted followers who are rooting for them ... to be on the covers of magazines and/or hosting SNL.