In a culture driven by media, these individuals tend to have as much influence over the popular mindset as our political, religious, and otherwise leaders. What's interesting is the shift. Environmentalism used to be un-cool. Each day more and more stars reveal themselves to be intelligent, soulful, and respectful members of our global community. In the pop culture analysis, a celebrity endorsement implies that green is cutting edge, and that our growing green economy is cool, rewarding, important, and for everyone.

Leonardo DiCaprio This star often flies commercially and drives himself around in a hybrid Toyota Prius. In 1998, he started the Leonardo DiCaprio Foundation to promote environmental causes. More recently, he's been working on 11th Hour, an environmental documentary featuring interviews with global green leaders.

Cameron Diaz This bombshell ain't trippin' (though that was the name of her eco-themed MTV show). The avid surfer drives a hybrid car, got trained to give Al Gore's climate presentation, and helped make the big announcement about Live Earth.

Robert Redford The Sundance Kid has campaigned for Utah wilderness, promoted solar energy, convinced mayors to tackle climate change, and served 30 years on the board of the Natural Resources Defense Council. In April, he launched a weekly three-hour slot of eco-programming on his Sundance TV channel.

Cate Blanchett Recently part of an ad campaign promoting Sydney's Earth Hour blackout, Cate and her playwright hubby have converted their own home to solar power. As co-artistic directors of the Sydney Theatre Company, the duo also plans to green that venture and hopes to power an entire theater season off-grid.

George Clooney This leading man not only earned an Oscar last year but also a prime spot on the cover of Vanity Fair's first green issue. In association with his award-winning role in Syriana, Clooney launched Oil Change, a campaign to say good night and good luck to America's dependence on oil. And to drive the point home, he's frequently seen out and about with his eco-friendly Tango electric car.

Ed Begley Jr. He is an electric-car-driving, solar-powered-home-owning star. He's got his own brand of eco-cleaners (Begley's Best), a reality show that puts a domestic spin on green issues (Living with Ed), and a morning routine that involves powering his toaster with a stationary bike.

Edward Norton The eco-commitment of this Hollywood heavyweight is no illusion. Norton used his star power to help launch BP's Solar Neighbors Program, which gets solar panels onto low-income homes in L.A., and he hosted an award-winning, four-part National Geographic TV special about the unnerving effects of global environmental problems.

Daryl Hannah Arrested last year for staging a 23-day tree-sit in a bid to save L.A.'s South Central Farm, an urban community garden, this steel magnolia is a longtime environmentalist who drives a biodiesel car and runs her green home on solar power. Hannah has also recently made a splash online with the eco-video blog dh love life

Julia Louis-Dreyfus Her solar-powered home is a showcase of green design and energy efficiency, and she's long been active with organizations like Heal the Bay, the Natural Resources Defense Council, and the Trust for Public Land.

Pierce Brosnan The world is enough for this 007, who focuses his activism on the planet -- marine mammals and wetland protection in particular. Brosnan -- who was named "Best-Dressed Environmentalist" in 2004 and serves on the board of the Environmental Media Association -- has long fought for dolphin-safe tuna rules and protested the U.S. Navy's widespread use of sonar, which can harm whales and other cetaceans.

Rosario Dawson Though she's soon to reprise her Sin City role, Dawson's environmental involvement leans more toward the virtuous. In 2005, she brought her star power to a U.N. summit on preserving the environment and ending poverty, and, more recently, she's dialed up her work with Global Cool's mobile texting campaign, which steers money to clean energy and energy-reduction projects.

Will Ferrell He got guffaws during his "Earth to America!" eco-comedy special on TBS, but this funnyman's commitment to the environment is no laughing matter. He's an active supporter of the Natural Resources Defense Council, and he'll soon be driving his electric car into the driveway of an eco-friendly home.

Tom Hanks An avid supporter and volunteer for The Nature Conservancy, this Forrest had the gumption to order the very first eBox electric car, delivered earlier this year. And Hanks often goes the extra green mile to make mention of his environmental leanings when he makes major TV appearances.

Brad Pitt Twice named "Sexiest Man Alive" by People magazine, Pitt isn't just a pretty face. A major architecture buff, he's been hot on the trail of the emerging green-building movement, helping with efforts to rebuild New Orleans in an eco-friendly way, narrating a sustainable design TV series, and supporting Ed Norton's Solar Neighbors Program.

Julia Roberts This pretty woman was featured on the cover of Vanity Fair's green issue last year -- and for good reason: She's a spokesperson for Earth BioFuels and frequently talks up green issues on Oprah and other TV shows. Plus, the Erin Brockovich star will soon be playing another green activist, wildlife conservationist Joan Root, who was shot and killed in 2006.

Matt Damon He recently narrated the documentary Running the Sahara and participated in the related awareness campaign about the water crisis in Africa. Damon also voiced the Journey to Planet Earth series on PBS.

Alicia Silverstone A longtime vegetarian -- and PETA's "Sexiest Female Vegetarian" in 2004 -- this blonde bombshell certainly isn't clueless about real environmental commitment. Silverstone is quick to talk the green talk in interviews, but she also walks the walk in her own green home, complete with solar panels and a table made from the flooring of an old bowling alley.

Matt Dillon He recently teamed up with Global Green USA and Yahoo! to announce a "Greenest City in America" challenge as part of the web engine's new "Be a Better Planet" program, which urges Americans to take action against climate change.

Charlize Theron She's traveled in eco-style to the Oscars and teamed up with a number of other celebs to fight the installation of LNG terminals off the coast of Malibu, Calif.