Google CSA (Community Supported Agriculture) and you should find a few schemes. We've got a lovely 4 acre field well away from the farm and I have often wondered about some kind of community pig / chicken / veg project on there. You would have to work out what's in it for you I guess and how much time you are going to end up devoting to it if you are the land owner / farmer. Can't quite get my head around it yet but it's an interesting thought. Maybe a big end of summer pig roast with a marquee and band, plus plenty of cider!