^You have a good point regarding food miles, cultcross
. The farmers' market I frequent sells only local produce, so walk away poorer but feeling very smug.
I agree that it's better to buy conventional local apples than organic apples from the other side of the world.
I read an article a while about about the environmental impact of food and their conclusion was to look for things in this order
1) Local organic
2) Local non-organic
3) Non-local organic
4) Non-local non-organic.
So that's what I try for these days.
Root vegetables are the ones you really want to try and buy organiic because the chemicals from the farming leach into the roots and with root veg that's what you're eating.