I've been closely "Proposition 37" (GMO labeling) in California. For what it's worth, I'm strongly opposed to anti-GMO legislation such as this. To be brief, I think that the labeling mandate would be burdensome and non-informative.
While I do sympathize with much of the criticism of the modern food industry, I think that focusing on GMOs completely misses the point. One of the points is the abuse of patents. In this case, it seems that patents are being used to stifle independent testing of novel GM goods. As I've written repeatedly, I think it's important that we severely reduce the scope of patents and copyrights, and I'd be comfortable with completely eliminating them. However, I don't think that's going to happen until the constrains of intellectual property affect issues that people really care about.