There are already Lego-compatible designs on Thingiverse (http://www.thingiverse.com/thing:591 http://www.thingiverse.com/thing:591), and the RepRap community i

There are already Lego-compatible designs on Thingiverse (http://www.thingiverse.com/thing:591 http://www.thingiverse.com/thing:591), and the RepRap community is working on the recycling aspect (http://www.3dreplicators.com/cgi-bin/cblog/index.php?/archives/423-Revisiting-the-recycling-of-Reprap-plastics.html http://www.3dreplicators.com/cgi-bin/cblog/index.php?/archiv...) We'll be there before you know it.