Mr. "Rishi" Sowa lives on an floating island. That he made. From empty plastic bottles and a few mangrove plants. In Mexico.
From the blog:
From 1998 to 2005, Rishi Sowa hand-built and lived on the first Spiral Island, which floated on over 300,000 recycled bottles! It was destroyed by Hurricane Emily in 2005. Rishi has now built an even better island at Isla Mujeres, Mexico, in a lagoon which offers shelter from bad weather! Rishi will continue to make improvements to the Island, so it will always be a eco-work-of-art in progress!
There's an online community of "Spiral Islanders" here.
(via BB Submitterator, thanks EeyoreX)