Very nice thread!
As for more ideas on helping the environment, I have a few daily things which can help a bit
1. Recycle! And no, I don't just mean the blue bins. People would be surprised that probably half the stuff fin their houses can be recycled. Most technology(batteries perhaps being the main exception) can be recycled and many retail stores can pick these up for you(I know we pick up technology at work).
2. Compost! Ok I know this isn't a given tactic for most people, but it does make a difference. Believe it or not, cow manure(or more likely just cows themselves) is one of the main producers of CO
2 and greenhouse gases. Now, we have large crops of cows, but some of them are used nearly exclusively for the fertilizer industry. Many people buy fertilizer when some of them contain chemicals/pesticides and promote this industry which is in the end damaging to the environment. Composting gets rid of your organic trash as well as provide "natural" fertilizer. Don't support the poop industry! lol
3. Use your car less? I know for most people this isn't feasible, but I know for others it is. Rule of thumb for me, if the destination can be reached within 30min and requires no bridge/highway(and some even don't care about highways & bridges), you can either walk, bike, skateboard or rollerblade there on a nice day. It's both good for
you and the environment.
Also, public transit is your friend... >.> Idk about the rest of the world, but Quebec has both Diethanol and electric buses so really, using the bus has become an even more "eco-friendly" way of transportation. Here, buses go to all the major places you need in town and it's a lot cheaper than riding your car(not to mention you cut half the traffic for rural living people like me

).
4. Stop using plastic shopping bags. Seriously, plastic bags are the bane of most environments >.> We've converted to using recycled shopping bags to do our groceries(and sometimes heavy shopping) an it works great! The bags are both eco-friendly and far stronger than those cheap plastic things at the supermarket. Best thing is that when they break(which only happened once so far), I can get new ones at work for free!

Not like they cost a lot either, most can be found for under 5$ and they last for more than one shopping session.
5. Don't throw(or at least try to throw away less

)! For most communities, throwing away stuff means they just bury it and don't do anything good out of it. Garage sale the stuff that can be re-used! One man's trash is another man's treasure! This way, you don't need to buy a new desk and support the industry who cuts tree after tree to make the wooden desks.
6. Buy equitable products. While this isn't directly related to the environment, it promotes smaller native makers rather than large industries, which usually are to blame for half the ecological man-made problems to date. Buying equitable products ensures fair pay to the farmer in Mexico or the Coffee brewer in Argentina and usually helps take their children out of those factories, effectively endangering those same factories.
Those are a few off the top of my head, but I hope I've made a decent contribution
