The London Wildlife Trust had an excellent stand with activities and, amongst other things, a Habitat Wall on display. I want to build one in the garden by the pear tree. They are beautiful- art meets insect home. Le Corbusier meets the beetles, if you get my drift (wood).
Easy and fun to construct and create, the instructions for doing so are here: http://www.wildlondon.org.uk/Miniguides/Creatingahabitatwall/tabid/443/Default.aspx
Not strictly anything to do with growing fruit, veg and herbs but I am going to incorporate this side project here as well and aim to have it in place by spring.