Christie's star-studded Bid to Save the Earth Green Auction is back.

The giant fundraising event, which benefits such organizations as Oceana, Natural Resources Defense Council, Conservation International and Central Park Conservancy brought in millions for charity last year. It includes an online auction in partnership with Charitybuzz and a luxurious and exclusive live evening benefit.

“Charitybuzz is thrilled to partner with Christie’s for the 2011 Green Auction, a truly unmatched initiative spanning nearly every industry in a bid to save our beautiful planet,” said Coppy Holzman, CEO and co-founder of Charitybuzz. “Building upon the success of last year’s unprecedented collaboration, this year’s online auction boasts a ‘who’s who’ of the world’s most iconic celebrities and industry leaders.”

This year's prize packs include some exclusive meet-and-greets with stars such as Lady Gaga and Justin Bieber, as well as prizes that go way beyond the standard "lunch for two."

For instance, how about spending an entire day with President Bill Clinton? How about a sailing trip with power couple Susan and David Rockefeller, or a flight with Harrison Ford in his personal aircraft? Perhaps most interesting is a day with Robert F. Kennedy Jr. to focus exclusively on falconing.

"You don't have to go Jurassic to hang out with raptors," the auction states. "Premier environmentalist and master falconer Robert F. Kennedy, Jr. will show you these noble creatures up close as you experience the thrill of this ancient sport. The magnificent birds will soar from your forearm and respond to your whistle, swooping at dizzying speeds."

Other opportunities exist to mingle with notables like Heidi Klum, Marc Jacobs, Michael Kors, Jayni and Chevy Chase, Karl Lagerfeld, Tory Burch, John McEnroe, Diane Von Furstenberg, Luanne Rice, Ralph Lauren, Carolina Herrera, Vera Wang, André Leon Talley and many more.

The March 29 live auction in New York will be hosted by comedian Seth Meyer, in collaboration with Runway to Green. According to the release, the carbon-neutral event will bring together "top art collectors, philanthropists, financiers and environmentalists with the fashion community."

Bidding on Charitybuzz is open now and will last through April 7. Jump over to take a look and help raise cash for green initiatives around the world.