I just put in bamboo floors and let me say for the record that they are gorgeous, supposed to be long lasting and sustainable!

I went to the Environmental Home Center here in Seattle (environmentalhomecenter.com) and purchased EcoTimber Bamboo (ecotimber.com). They raise their bamboo on farms in China making it sustainable, and pay their employees fair wages, provide them with housing and health care and generally do things right. Look into them.

Recovered hardwood is another excellent ecologically sound flooring option, if you can find it in your area.  Our kitchen and dining room floors were once in someone else's house, or possibly belonged to a recently-remodeled high school gymnasium.  Either way, it's a very tight-grained oak that's all but impossible to come by these days, and it went into our house instead of the dump.  The Rebuilding Center here in Portland is a great source for recovered materials from remodels and demolitions.

For our new office flooring we chose Interface FLOR as an environmentally sustainable choice that was more affordable than cork or bamboo. We've ordered it and it's ready to install as soon as the room is done. It looks like it will work as expected, although we don't have any personal experience with it yet.
The reasons we chose it were: 1) The company will take it back for recycling at the end of its lifecycle; 2) The tiles can be rotated for even wear and stained tiles can be replaced, making this a longer-lasting investment of resources; 3) It supports a company that is working to create an environmentally sustainable business model; 4) Some of the styles are natural materials; 5) Not to be overlooked is that it's stylish as well as sustainable-the only way to be successful; 6) It can be installed by the homeowner; 7) It can be moved from room to room or house to house, increasing its useful lifespan.
Hopefully, we've made a good choice - we'll see after we install it and live with it a few years!

being Portuguese, I'm extremely happy to have you recognize how well we treat our trees!!!
It's all true.
I had cork floor for many years, and indeed it is very soft, comfortable and warm.  However, being a dog lover, and having three - now, that one has unfortunately passed away -, I had to take it off and lay a new one, very cold and uncomfortable tiled one, but easy to clean.
Keep up the good work!   I simply love your advice.

I also installed bamboo floors.  Our local dealer in Seattle assured me they were twice, thats 2x, as hard as oak according to lab tests.  Well I am here to tell you they are fragile, dent and scratch easily.  Beautiful, yes, until you drop something on the floor.  We have fir floors next to bamboo - no comparison, even the relatively soft fir is superior to the bamboo by far.  Further evidence is my gym's yoga studio - bamboo floors - all scratched and dented.  What could possible scratch and dent a yoga studio floor.
Think twice before you put bamboo in any areas where you will be active, or if you have a dog, or in any traffic areas.

Hmm, is bamboo flooring really that good? I didn't know that bamboo is
that sustainable. I'm using ceramic tiles by the way. Interesting tips on carpet flooring. Now, I'll know which best for me if I were to change my carpets.

I know I'm replying to a few older posts, but the conversation is relevant to me.

I'm desperately looking to replace my carpet ... and have three dogs also...

What are some choices that are not only sustainable, but durable ... in addition to tiles?

THanks.