I get all my seeds from either Baker Creek or Seeds of Change.
I only grow heirlooms. I do it not only for myself but because I've heard it's healthier for the bees.

My objection is not to the genetic modification itself - we have been doing that since the first farmers - but the stranglehold it gives the big companies over the seeds, the damage some of the modifications may do to the environment, and other side issues.

Well studied GMOs are not a threat to anyone.

Say NO to GMOs

GMOS are our ruination. They allow farmers to broadcast poisons like Roundup which don't touch the GMO but kills everything around it. And then we eat it!
Say NO to GMOs

I fear what happens when they escape into the world. Hybrids like africanized bees.

Maybe it's because I studied genetics and microbiology for 3 years that I don't trust GMO's and I am NOT saying that there is anything dangerous about GMO's just that I don't trust them because I don't trust the Agribusiness players behind almost all of the GMO foods. The FDA used to be a check against abuses by industry but that hasn't been the case for at least a couple of decades now, most of the top people have direct ties to the big Agribusiness players so we really don't know what genes are being manipulated and what the knock on effects may be.
I grow with heirloom seeds even though many of the heritage seed banks have been bought up by the same corporations that are producing the GMO's, many of the seeds I plant I trade for and I replant from previous year's harvests as well. We are what we eat and until I can be sure I know what I am putting in my mouth I will minimize my intake of GMO's, the same goes for the meat we eat, I shop locally for the most part and I am pretty confident about the amount of steroids, growth hormones and antibiotics that are being used but I am fortunate and live in a rural area.

I generally avoid them, don't trust them. I'm not going to die on that hill, but I will avoid them if possible.

I have seen no actual evidence of danger. I have both heirloom and gmo plants. Some heirlooms are second generation. If I saw actual evidence that gmo crops were harmful, I would change the way I feed my family.