I live in Ecuador and can speak to the destruction that palm oil is causing. Palm oil is the current driving force behind the near-100% destruction of the western Ecuadorian rain forests, and production is starting on the eastern (Amazonian) side.
Before this, it was cattle. The root problem is not any particular crop, but the existence of so many people in Latin America that want western developed-world lifestyles and cash flows. This is unfortunate but understandable given the difficulty of rural life in western Ecuador (read "A Farm on the River of Emeralds" for an insightful view of life here for poor people--it is a classic, unique book). Solutions are difficult to find.
Here in South America, palm oil is touted now for biofuels production, so even if we stopped eating it, this would not end its production. Biofuels are a political and economic scam that all of us should fight. Many studies have shown that when crops are grwon specifically for biofuel production, the energy used to grow, harvest, transport, and convert the crop is about the same (and sometimes less than) the amount of energy produced. This makes no sense and will destroy virtually all remaining undeveloped arable lowland tropical forest.
LJ