I'm a little late to the party, but I should point out that there is a big, BIG difference between "Organic" meats, and "Grass Fed".
Organic is a certification owned by the government, where meat (or produce) qualifies under set criteria. This can (and does) include beef fed and finished on grain, in a feed lot. Just because it's organic, doesn't mean it's better for you.
Grass fed, or free range, has nothing to do with the term "organic". It is beef that is raised free range, and is not finished on grain or in a feed lot. Azure posted a site that explains it quite well.
http://www.eatwild.com/healthbenefits.htm
I grew up on a ranch, and we specialize in grass fed beef. It's steroid free and for the most part antibiotic free, as the cattle are largely show cattle.
Both books by Michael Pollen are an EXCELLENT resource on the human diet nowadays. I suggest people read those too, although they're about as dry and boring as they come.