I'm not sure how I've missed this until now. In 1996 (!) artist Ha Schult created an army of one thousand life sized figures completely made of trash. They have been installed in high profile spots like Moscow's Red Square (1999), The Great Wall of China (2001), and The Pyramids of Giza (2002). It's difficult to tell from the the info I can find online if the installation in 2008 in Antarctica was the grand finale, or if there are plans for future installations. If so, I hope to catch one at some point.
Find out more about Ha Schult and his work.