ecoBlog
A classic, minimalistic eco blog theme. Mostly lush green, with a tincture of other colors. Bundled with ecoBlog is the funky ecoSocial widget, and all this goodness is yours for free!
ecoMicro
If you are a fan of Tumblr or Twitter, ecoMicro is your friend! An ultra-minimalistic, microblogging theme. Customize it to get the ‘microness’ you want. Add inline comment snippets to your homepage to get the conversation going. Even ought to, it is completely free!