Rumer Willis, Kristin Cavallari, Christina Milian, Josie Maran, Pete Wentz, Corbin Bleu and Wilmer Valderrama are lending their celebrity to the Spring/Summer 2008 ad campaign of Wal-Mart’s junior’s line, Op. Op will launch exclusively at Wal-Mart and walmart.com later this Spring.

The concept of the campaign is “OPen Road” and celebrates Op’s historical open road California lifestyle, which the brand has represented since the original launch in 1972. The campaign will continue to follow the Op cast as they head into fall with a back to school campaign that will debut in August, Wal-Mart said in a statement released to the press on Wednesday.

“When you think of LA and the classic surfer beach vibe, you think of Op. The Op collection does a great job representing that lifestyle,” says celebspawn Rumer Willis.

Fall Out Boy’s Pete Wentz agrees: “Everyone can wear Op and its cool. Fashion should make you comfortable and that is what Op does.”

You can learn more about Op by visiting the line’s Official Website, Op.com.