I read about this in the December 2007 issue of Money.
You can select from over 1600 farms and pickup the freshest produce.
Anna Lappe who co-authored the book "Grub: Ideas for an Urban Organic Kitchen"
The site is www.localharvest.org/csa
Cost is 350-500 for 20 weeks of produce.
This sounds like a very good deal. Comes out to 25 per week for produce for your your family.
It's work checking it out.
Let me know what you find out.