IsometrIcon is a free Photoshop plugin that helps to transform shapes into isometric orientation.

IsometrIcon is a free Photoshop plugin that helps to transform shapes into isometric orientation. Build simple isometric icons and other elements in seconds with only a few clicks. A true time saving tool for graphic artists and icon build

Interesting idea, but you need to watch the tutorials first! For Photoshop CS5 and above.
http://www.the-orange-box.com/portfolio/isometricon-free-photoshop-plugin/