The tiny house movement seems to be growing. At the extreme - those less than 200 sq ft - can be a bit different, with some even being mobile, but perhaps 500 sq ft is enough for many people who are thinking in terms of less consumption and owning things outright rather than being in debt... As the US becomes more unequal and the American dream is shattered, the notion may gain in popularity. There are a lot of unemployed architects and designers these days - this area may be a very fertile one that could couple with their imaginations.
Here is a trailer to the upcoming We the Tiny House People documentary by Kirsten Dirksen. Some of her examples are urban, others tend to be rural. Some very clever uses of space.