Trash rocks can be used as benches, tables, sculpture bases, landscape accents, and walls. A family living in one location over time could build a castle out of their trash. I would expect trash rocks to have good thermal insulation, useful in both hot and cold climates.
I'm big into recycling and built my whole house out of recycled nylon fishnet and cement, a material I call nylon-cement. For many years I eliminated all my trash right at home using trash rocks.
Ideally, I would like to see a chemist develop a way to recycle some of our plastic trash and make a mesh material like fishnet out of it that could be plastered with cement.
Recycling is all about mining trash; converting waste into something useful. If we separate our trash first and put it into separate trash rocks we would know where to look for specific recyclable materials in the future when we need them. In the meantime, why not enjoy living around all the trash we generate?
Step 1: Scoring the Fishnet
Then I found the free fishnet mother load of all time right under my nose, the StarKist tuna factory. They were very helpful to me in saving used fishnet that the boats wanted to get rid of. Discarded netting is a trash disposal problem for the factory, so we helped each other out.
After getting it home, the fishnet was opened out, cleaned off, rolled up and stored outdoors. It smelled "fishy". Given a month or two of exposure to rain and air it was completely user-friendly. Fortunately, I live in the country, where I can do this without offending the noses of neighbors.
Good luck finding a source of your own. Fishing ports and fish farms are good places to start looking for used fishnet. Ready-made trash sacks that can be plastered with cement should be available for this idea to really take off. Sewing your own sacks allows you to make different sizes of trash rocks, but ready-made sacks would save some time and effort.
http://agriculture.exportersindia.com/aquaculture/fishing-nets.htm This is a link to manufacturers of fishnet. Most are in the Orient.
http://www.thomasnet.com/nsearch.html?cov=NA&what=Netting&heading=53680203&navsec=prodsearch A search for "netting" on Thomasnet can come up with U.S. manufacturers.