Last year we reported on Ecuador's offer to protect the bio-diverse but oil-rich Yasuni National Park - if the rest of the world paid Ecuador half of the value of the oil that lies under the park's rainforest.

Now it seems a motley coalition of governments, local authorities, movie stars and individual donors has put up the initial deposit of $100 million, which Ecuador demanded by the end of 2011 to hold off the oil companies.

It's an interesting proposition in two ways.

Firstly, Ecuador is asking for payment NOT to do something. The idea of paying countries, or companies, not to destroy the environment is controversial. Critics believe it could lead to a form of blackmail - threaten to destroy a rainforest or whatever, then demand a cash payment not to do so.

Secondly, it's an example of "crowdsourcing" - raising funds from a large number of often-small donors who support your aims. The makers of The Age of Stupid used the same approach to fund that movie.

If it works, Yasuni could offer a new model for conservation.

But the deal is far from done yet. Ecuador is demanding a total of US$7.6billion to take the park off the oil market for good.