This is a bit off the direction y'all have taken, but I have to chime in (responding to the initial post) in favor of buying locally produced food whenever possible -- it's almost always fresher and more nutritious than supermarket foods. It has a much lower carbon footprint for not having traveled thousands of miles.
The money you pay for local food goes to local farmers and local small shop owners, and money spent like that tends to stay in the community and have a multiplier effect, while money you spend at big boxes flies out of the community so fast it costs a bank to have a Wal Mart account (the money never stays in the local bank long enough for them to have any benefit of it being there -- all they do is work for WalMart for free or at a loss, or so my bank VP pal tells me who thought his bank was so smart to sign up the new WalMart's account when they came to that small town in Alabama).
Sorry for that poorly crafted ramble, I really oughtta be mailing Christmas gifts right now. Happy Holidays, and y'all come on out to Seaside Farmer's Market to support your local farmers!