Bale Gardening

I cam across an article about bale gardening the other day. It is a method where you condition a bale of straw and then plant in it.  The picture in the article showed a bale strapped to a city apartment railing with all kinds of vegetables growing out of it.  It is an ingenious way to contain plants on a balcony and grow your own food in the city.  I don't have an apartment, but it would be cool to try this method in my garden for some of the things that I want to grow.