Trippin' (MTV)

Actress Cameron Diaz and celebrity friends such as Drew Barrymore, Jessica Alba, and Kid Rock go globetrotting-for-good in this offbeat reality show. They hit a different locale in each episode, learning about threats to barrier reefs in Honduras or rain forest destruction in Chile.

This is still MTV, so it's not purely educational. There is drinking, some mild language, and, in the Honduras episode, lots of shots of Diaz and Alba in their bathing suits. The celebs mingle with the locals, which is sometimes cool (surfer Kelly Slater catches waves with local kids, all of them using disused lumber), but sometimes patronizing (as when Diaz asks a local man how many children he has). Diaz is a likable enough host who seems willing to do just about everything. Viewers see her handle a pink python she spots in the wild, and eat honey straight from a bug's booty. And MTV should be applauded for trying to do something more educational than Punk'd.

But, while there are some earth-friendly facts flashed across the screen throughout the show, the eco-premise just isn't cohesive enough, so in the end it doesn't seem completely sincere. The celebs arrive at a beautiful spot, learn about a big problem, explore a bit, meet some people, then leave. If they did more work while they were there -- or if Diaz assembled a complete cast of stars who really got into the project -- it would make for a smoother ride.