Photo by: Milk Processor Education Program
The All-American Rejects Sprout 'Got Milk?' Mustaches
The All-American Rejects have a "dirty little secret" – they're milk drinkers!

The rock quartet, best known for the top 10 single "Dirty Little Secret," recently joined the likes of David Beckham, Beyoncé, Martha Stewart, Muhammad Ali and Mike Myers as Austin Powers among the milk-mustachioed stars who have appeared in the "Got Milk?" ads.

"They're all very iconic," rhythm guitarist Mike Kennerty tells PEOPLE. "It's definitely a big deal. The only thing bigger than 'got Milk?' are those T-shirts that rip off the saying by asking 'got' something else."

Lead singer-bassist Tyson Ritter says of the shoot by revered celebrity photographer Annie Leibowitz, "It was completely humbling and an honor to do it."

The ads promote the nutritional benefits of drinking cow's milk. Kennerty says healthy living is not hard for his group, which also includes lead guitarist Nick Wheeler and drummer Chris Gaylor. "On the road we're just active every day," he says. "We're playing shows. So that really does help. It's when we come off the road that we're not doing anything but sitting around drinking – that's milk of course."