It's nearly summer, and Nicole Richie has the look to prove it. Hollywood's petite fashionista hit the right coast in a casual maxi dress for the launch of House of Harlow 1960 Jewelry in Miami Beach.

We're not in high school anymore, Toto! 90210 resident Jessica Stroup swaps her on-set school wear for a fun, sophisticated ensemble at the Alberta Ferretti & C.H.I.P.S 2009 Spring Luncheon in Beverly Hills.

All the platinum-certified pop hits in the world can't save Leona Lewis from a dress that's a little too tight in all the wrong places. But we'll admit this body-hugger, which she wore to the preview party for Herve Leger by Max Azria, is a giant, sexy step up from her Grammys body-sock.

Where's the disco ball? We'd love to hit the dance floor with Taraji P. Henson and her groovy little low-cut number at the Herve Leger preview. (Although we might also bring her some double-sided tape before the dance-off.)

Is it just us, or were the ladies at the Herve Leger event strutting their stuff a little more prominently than usual? One Tree Hill siren Sophia Bush makes us blush in her white-hot ensemble, striking a naughty balance between seductive and straight-laced.

Did Kate Hudson wear a suit to prove she's down with the smart set? The queen of romantic comedies got all business on us for Time's 100 Most Influential People in the World Gala.

Gossip Girl star Blake Lively is smokin' hot and working it hard at the Met's Costume Institute Gala, but her one-sleeved ode to the era of big hair douses her smoldering look.

Jessica Biel's got it going on at the Costume Gala, and having her super-star, bespectacled BF by her side doesn't hurt.

OC alum Rachel Bilson is undeniably hip, hot and glamorous at the Met Gala. But her vampy hair and barely-there attire seem better suited for a night at some Hollywood hotspot than a fashion-tastic night at the museum.

Yes, Tyra, the event is a "Costume Institute Gala," but it's a metaphor. Of course, being a former model means you can make just about anything look good — but it doesn't mean you should try.

Why are we not panning this unusual ensemble without so much as a second thought? Because being sassy has its merits. Gossip star Leighton Meester shows us what a "fashion risk" looks like at the Met Gala.

Leave it to Heidi Klum to push pregnancy chic to the limit (and then some) at the Costume Gala. The model-mogul embellishes her growing girth with layers of taffeta and silk, while her wink-wink hint of leg bears a message to moms everywhere: Kids or not, you're still smokin' hot.

Yeah, OK. We've seen Diane Kruger and Joshua Jackson pull this perfection on the red carpet before. At the Met party, the couple makes a stunning entrance yet again. We just hope they relaxed once they got inside.

Leave it to Jessica Alba to dazzle in a mixed-media dress of sequins and silk. On some women, her Met party ensemble might be more Dancing with the Stars than elegant evening attire. But we learned long ago that the Hollywood beauty isn't "some women."

Rihanna glams it up for the Met Gala, getting sexy and serious in a silk tux, heels and sculptured 'do.

Liv Tyler's vintage-style, shimmering dress at the Met event is equal parts hip and sophisticated. The part we can't get over, though, is the one that evokes Cher in Vegas.

We get it: Anne Hathaway is tired of being the elegant good-girl. In fact, she's so tired of it that, at the Costume Institute Gala, she channeled Brigitte Bardot and that edgy dude from Project Runway who was into zippers — at the same time.

Unveiling the next Moore-Willis progeny! Scout Willis (r) shows she's got some of the family style genes in a functional, fashion-forward outfit at the Nylon Magazine and MySpace Young Hollywood Issue party. Her sis, Rumer, keeps it formal in a jagged-hem, strapless number and rock-star heels.