Options are limitless, however, I'd recommend incorporating a human into the logo to illustrate that human beings are key pieces in Permaculture systems. It would also help to illustrate that we humans are a part of Nature and not separate from it (one of the roots of our environmental problems). This all seems especially important for a Permaculture organization in an urban area like Seattle.
That's my two cents...
Principal - Terra Phoenix Design
Hi Kelda, how are you? I joined this site to find out more about permaculture and hopefully to take classes. I live as you know in the South Sound and I am in need of green renewal. I think a logo with a circle somehow. I saw a celtic symbol tree of life that was modified that looked cool.
As far as where logo would be used, a friend has started a place called www.heartgardens.comheartgardens, and as part of the outreach/funding project has used networks to various groups to make the project appetizing to new folks. It's a good idea. The logos are like lots of little stamps of approval on the back of the brochure. And though Seattle Permaculture Guild gives him no money, anyone would agree it's a cool project to 'support'.
It's timely to think of a logo for us anyway. To have something to refer to for any publications we make as a group. I like all the ideas. Maybe someday soon I'll try to draw something up and post it here as a picture. I invite others to do the same