A number of companies make tankless water heaters. This is something that could save an enormous amount of energy. They cost more, though, but mass production would be a boon. The electric ones seem to be the most economical. Here's an interesting site that discusses the pros and cons (scroll down to FAQ): <A HREF="http://www.plumbingsupply.com/index-tanklesswaterheaters.html" target="_blank">http://www.plumbingsupply.com/index-tanklesswaterheaters.html</A>