Curt Lindley, a Peace Corp worker in Mandeville, Jamaica, just sent us pictures of a one-bucket design that he's developed.
1) Cut the top off of a water bottle (we'll call it the "top")
2) drill a a number of holes into the top
3) cut a hole into the top for a watering tube
4) attach (with duct tape?) an absorbent acrylic fabric over the top's opening (the yellow fabric in the photo)
5)Turn the top upside down and place it into the bucket
6) fill with potting mix
Below are some pictures Curt sent us. Curt (in the black T-shirt) and some fellow Peace Corps volunteers are at a school in Jamaica making 30 "buckets" in one day in May 2010. Click on the pictures for a larger image.