Some MBW participants share seedlings, seeds, and other garden and allotment stuff as well as advice, books and so on. MBW is interested in linking up with various community projects involved in organic and environmentally-friendly and fair gardening and farming practices.
Here are some links to follow up:

Federation of City Farms & Community Gardens
http://www.farmgarden.org.uk/

Cultivating Communities
http://www.cuco.org.uk/