Cameron Diaz is "Trippin' "— and she assures us it's not just a star trip.

She is, however, the star and executive producer of "Trippin'," the new MTV series that's part travelogue, part environmental primer, part extreme challenge — and, yes, part star trip. Beginning tonight at 8:30, Diaz and her celebrity pals travel to various exotic sites, participate in various cool stunts and do their fair share of tree huggin'.

"It's really about the message, because otherwise there's really no other reason to do it," Diaz recently told TV critics by satellite link from a Chilean rainforest.

So . . . what's the message she's trying to deliver?

"The message is that we only have one planet and we're all related," Diaz said. "Our population has grown so rapidly and so has technology, which has brought us all closer together. But what we've learned from that is we've become a global community. And . . . everything we do affects one another all over the world.

"The ecosystem is a very well-constructed system that functions in a way that if we start losing too much of one thing or many things, we offset that balance."

So, rich, famous people getting to travel to exotic locations are going to make MTV's young viewers think about saving the planet? Well, that's the plan.

"It's about the message, the whole show," Diaz said. "But we have a lot of fun doing it. We want to entertain the kids. We want to give them something that they're going to be surprised at seeing and have fun watching."

And, message or not, fun is what MTV is all about. Well, mostly about.

"When Cameron Diaz told us she wanted to highlight a cause she felt passionate about, which is global conservation, we jumped at the chance to work with her," said Lois Curren, MTV's executive vice president of series and movie development. "Our audience loves to care. They just hate to be told how to care."

Yeah, we know. You can't tell teenagers anything.

But Diaz is going to try. "We're trying to do is give it to them in a way that is easily digestible for them that they will want to take it, and they'll be learning because of the way that we're giving them the message," she said. "If we understand that, then kids might start looking at it differently. They might start looking at how they consume, what they consume, where they consume it from."

And she's going to try to get that message out even if it means she has to — gasp! — put herself on camera.

"I hate cameras. . . . You don't really want to be followed around by cameras all the time," she said. "But if you're going to have to be, this is a good reason to do so."