Jessica Szohr Gossip Girl OP Walmart ad campaign purple shorts string bikini top

"Gossip Girl" star Jessica Szohr keeps it casual in a bikini top and purple short shorts while posing for the Op ad campaign. Photo courtesy of Op

Ah, summer. Time for barbecues, bikinis, and hanging with your beachy-keen celebrity friends.

The 2010 ad campaign for Op's sweet, sexy, and affordable line features an attractive melding of cast members from "Gossip Girl," "Glee," "90210," and the "Twilight" films engaging in a fantasy summer block party.

In the aptly named Rock Your Shine campaign, "Gossip Girl" star Jessica Szohr hangs in a hammock with "Glee" cast mates Cory Monteith and Dianna Agron, while the rest of the ad's stars -- including R&B singer Cassie, "90210'"s Trevor Donovan, and "Twilight"-er Alex Meraz -- flip burgers, play cards, or head out for some surfing.

"The clothes are great; especially the amazing bikinis and shorts," Szohr told People of the unisex line, which is available exclusively at Walmart.

A spokesman for the Iconix Brand Group, which produced the collection, told the magazine that all of the stars really did have good vibrations while making the ad. Perhaps they did an impromptu Beach Boys medley?

We checked out the sand-ready goods, which range in price from $12 to $24, and thought the colorful board shorts, swim separates, and strapless bandeau sundresses were especially cute.

The Op ads, due out in May, will be featured in fashion magazines as well as online.

Check out the below video to get in on the action.

In the meantime, get more "Gossip Girl" style.