I could write a book about my thoughts on this, but here's the short version:
1. Organic food has been discussed multiple times throughout these forums, with thorough viewpoints presented
2. For overall carbon footprint, eat locally and seasonally, then organically. It is much more trying to grow organic produce on the east coast. West coasters grow it and ship it thousands of miles for your local grocery store-check the signs. Also, local conventional produce picked yesterday will always taste better than produce picked thousands of miles away several weeks or months ago.
3. We are talking about trace amounts of pesticides here. While they may possibly effect the endocrine system, it's a tiny amount. Most things you eat out of season will have fungicides on it because the place where the produce was stored need to prevent disease from spreading.
4. Spend your money as you wish. Buy organic, but look up the regulations and know which pesticides and production methods are allowed. There is an allowed list of synthetic pesticides and an unallowed list of nonsynthetic/natural/organic pesticides (I can't remember the correct word).
5. Both production methods can be done by large farms or small farms. Both can even be done by the same farm.
Generally speaking, eat your fruits and veggies. Read about what being certified organic actually means, and if it's important to you, know your farmer.
Also, in my class on Sustainable Ag in college, we talked about "feeding the world". Most of it comes down to increasing acreage in Africa. Overall bushels/tons/etc. per acre grown here in the U.S. will definitely go down if switched to exclusively organic methods, but that would be covered by increasing acreage in Africa. For our situation of produce on the East Coast, we would have to increase cover sprays to fight disease infection periods, which using the same number of people means we have to decrease acreage we manage. Also, we would have a higher % of "ugly" fruit, so our overall production would go down. Even using conventional methods, the main goal of feeding the world big-picture comes down to increasing production, storage, and transportation systems in Africa. My professor published a paper on it, but I'm too busy right now to go look it up.
Finally, conventional growers incorporate some of the practices mentioned in the organic certification, just not all of them. We personally also do most of the things in the "good" and "better" categories of the new Whole Foods rating program, but because of two specific pesticides we use to fight very specific insects, we go "unrated", which is code for failing.
There are more varieties of apples available in your local supermarket shelves than there were 20 year ago. The average number of varieties has doubled. But we all eat one variety of banana and oranges are sold as "oranges". I think that has more to do with corporations (both farm and store side) than conventional vs. organic.
People confuse organic with local/natural/seasonal/heirloom. I can grow heirloom apples conventionally and sell them to a neighboring farm to sell in their farm market. These things aren't the same.
Well, that's a lot more thoughts than I planned to write out. I'm sure you can tell my family works on a conventional produce farm. :) But anyone can buy organic food if they want to, go for it.