There are many seed sources which pledge that their seeds are not GMOs. I personally purchased seeds from Seed Savers Exchange (a non-profit org. dedicated to preserving rare and/or heirloom varieties of fruits and vegetables) and from Baker Creek Heirloom Seeds earlier this year.

I'm sure others here will recommend other companies; I can personally recommend these two.

in el cerrito

I would definitely recommend Baker Creek Heirlooms, also. They have a great variety and great service.

I completely forgot: check out the Garden Watchdog at www.davesgarden.com to get ratings of gardening companies that do business via mail and Internet.

in el cerrito

I like Pinetree Gardens in ME - they're a small co. & offer lots of heirlooms for small home gardens....

Southern Exposure Seed Exchange is dedicated to heirloom preservation as well:
http://www.southernexposure.com/

Here is a link that might be useful: Pinetree

Another vote for Baker Creek. They rock.

On my last shipment, one packet was overstocked due to "low germination rates". It still came up 100%.