As I'm sure you're aware, I do quite a lot using my weekly veggie delivery box from Slipstream Organics, and anyone who knows me, knows I'm a massive supporter of British farming and local food. I posted this as a link in response to one of the comments for a post, but thought it would be useful for everyone else to see as well.
For those who'd like to support their local community by buying fresh, local (and often organic produce), check out the links below. They're both really useful for finding Farmers' Markets, local delivery schemes and much more as well.
For anyone in the UK, have a look at Big Barn
For those in the US, Local Harvest is probably the biggest and best directory.