Ikea and solar lights!

Solar lights are becoming common - go to a Canadian Tire or Wal-mart and you'll find outdoor solar lights to trail your driveway or walkways.  Ikea is starting to sell solar lights as well:

http://www.ikea.com/us/en/search/?query=solar+light

Cleaning your indoor air with plants

According to a Lifehacker post: Three Plants that Give you Better Indoor Air:

Areca Palm

Mother-in-law Tongue

Money Plant

http://lifehacker.com/5149643/three-plants-that-give-you-better-indoor-air

Using mines or running water for a source of energy

I've seen this done with an old mine out in the interior of British Columbia. Essentially, some fellow ran a turbine through an in-mine stream to generate electricity. Here's another use for an old mine: Geothermal energy

http://www.inhabitat.com/2008/12/10/heerlen-minewater-project/

Spray-on Solar Cells

You can now spray on solar cells:

http://www.livescience.com/technology/081106-tiny-solar-cells.html

Affordable Solar Panels

Solar panels have always been rather expensive. But there is some hope:

http://www.industryweek.com/ReadArticle.aspx?ArticleID=14932

I can only hope that by the time we're ready to build, that panels will be as common as dry-wall.