Eating meat is one I vascillate between also - I eat organic meat now - however I do believe that it leaves a far bigger and less manageable footprint than a vegetarian diet.
I have always disagreed with this. Cows don't care if their are trees and hills on their field. Crops do.

Mans way of breeding cows for consumption is what makes its less ecologically sound. Its exactly the same as mans way of agricultural farming. The only way to minimise your footprint through food is to go purely organic and live in the country where the food is bred and grown.