There's an article on WebMd explaining the current orgo situation. Here's a sample:
Why Organic Especially for Children?
Children are developing organs to last a lifetime. Due to their smaller size, fast-growing speedy metabolisms, and less varied diets, infants and children are more vulnerable to health and developmental damage. In 1993, a congressionally mandated study by the National Academy of Sciences expressed concern that existing methods of risk evaluation for pesticide exposure were failing children. More recently, the Consumers Union and Environmental Working Group have released studies confirming that children are overexposed even if their exposure is within legal limits.The Food Quality Protection Act of 1996 mandated a review of agricultural chemicals in light of this new information about risk assessment. Included in this act is a requirement to impose a 10-fold margin of safety to protect children when setting standards for the use of pesticides on food. While safety standards have become more strict, buying organic products, if they are available and you can afford them, and supporting organic agriculture may be your best protection.
Great, a good article, and then I read about the author. Dr. Alan Greene, a professor at Stanford (impressive, no?), also the founder of the website DrGreene.com - and the author of Raising Baby Green: The Earth-Friendly Guide to Pregnancy, Childbirth, and Baby Care. In other words, of course he advocates organic food for children.
Do we know for sure that eating organic is better? No, the research is probably years away. Dr. Greene acknowledges this, to his credit. Do we have some evidence children who eat organic have less potentially harmful chemicals in their bodies? Yes. Do we know if those pesticides and such have ill effects? Not yet. Do I buy lots of organic food? Yes. Can I afford organic produce? Yes.
Check out: The Organic Buying Guide on Babble.com - an article that also talks briefly about the pros and cons of organic food and a list of foods you should buy organic and ones to "stop worrying about"...