To Till and to Tend

My cousin mentioned that at her minyan, Lomdim in Chicago, they showed The Gleaners and I on Shavuot, thematically tying in the activity of Ruth to contemporary behaviors.  Gleaning is the biblical precept of leaving the corners of the fields unharvested so that the poor can collect grain for their sustenance.  In contemporary times, there is still a gleaning movement.  The Society of Saint Andrew is dedicated towards salvaging crops for the hungry, accomplishing two mitzvot at once: feeding the hungry and avoiding waste, bal tashit. 
In urban contexts, there are many food salvage programs that help feed the hungry, like Second Harvest and our local Philabundance.  Another trend developing, is called Freganism.  Fregans dumpster dive and trashpick as a life style, calling attention to the astronomically wasteful American lifestyle.  Generally fregans have opted out of a high consumption lifestyle and, not being homeless, are a different demographic than people who live on the streets.
The Internet iscleverly utilized to match givers and gleaners.  My personal favorite is freecycle.org - there are thousands of local freecycle groups where folks go daily to offer and request items.  My latest give-away was two bird-feeders that were attracting more squirrels the feathers; my next request is lined 3-hole paper.  Most households have a lot of that sitting around at the end of the school year!
Many freecyle(TM) participants post things we see on the street, dubbed "Curb Alerts".  Much akin to gleaning, people leave items up for grab on the corners of their driveways.  One question which comes up on Freecycle lists is whether it's ok for people to resell items claimed via Freecycle, on Ebay or at flea markets.  I say that's great.  It's helping people to earn income, keeps things out of the waste stream, and since the donor was obviously too lazy to bother, the reseller is offering an environmental service.  Craigs List also has a large section of free items. 
Whether you glean out of ideological conviction, for sport, or from need, it is an ancient and wonderful system!