A recent news item, found in the "Purdue University News", shows one possible future of garbage.  At least it is the future that the U. S. Military has in mind. Garbage has always been a problem, especially in times of emergency, when the normal methods of garbage disposal stop working.  The U.S. Military has funded the development of a Tactical Biorefinery at Purdue University. This device converts garbage of various kinds into energy and produces 90% more energy than it consumes.  

It is designed for emergencies like the Katrina Hurricane Disaster but could be adapted to a more conventional operating form. Appropriate Technology for a highly specific set of circumstances, but I am sure it can be modified and expanded to serve in more common everyday situations. Landfills may come a thing of the past.

For More Info: http://news.uns.purdue.edu/x/2007a/070201LadischBio.html