One of my favorite companies for many years has been Patagonia, albeit pricey, but environmentally aware:
Since 1985, Patagonia has pledged 1% of sales to the preservation and restoration of the natural environment. We've awarded over 31 million dollars in cash and in-kind donations to domestic and international grassroots enviro groups making a difference in their local communities.
Just reading their website (before you shop, of course) is an education. Not surprisingly, they've added a cool section to their website on "The Footprint Chronicles" which traces the footsteps of select products they manufacture and sell. They start by telling you, "there's no such thing as a sustainable business" which in their world and products they sell, may very well be true. They know the carbon footprint left in their business and production line is massive, so they focus on recycling, making sure their products are made in fair, safe, legal working conditions, and practice resource conservation along with assuring their buildings are LEED certified (including building their own solar power plant for one of their buildings!). Following the footsteps of a garment is interesting -- it made me realize even the organic garments aren't necessarily the best choice (distance traveled - water consumption to grow the organic cotton). The one that truly astounded me was the distance wool travels -- 16,200 miles. How do you put a carbon pricetag on something like that? Scary thought. Maybe we should all stick to 2nd hand clothes, and just skip the underwear?