The idea of crops mobs has been getting some press lately (most notably in the NY Times). The idea is pretty simple: landless farmers, gardeners, and wannabe farmers get together and mob a farm helping weed, prepare soil, build farm structures and do other labor intensive farming work.
Volunteers help build a chicken coop at Felder Farm in Little Rock, AR
Crop Mobs are popping up all over the country and the website CropMob.org has plenty of tips on how to start your own.
Gather some friends, advertise it on Facebook, and get your hands dirty helping a small farm grow good, sustainable food.