Here's the link to a 20-minute animation called "The Story of Stuff" you must watch. It talks about what we, as a disgustingly consumerist society, are doing to our planet.
It's a straightforward yet powerful presentation, which after watching (if you have any conscience) will stall you from shopping for a while, and hopefully make you think seriously about what you can do to help the dismal state of our Earth today.
So get a cup of coffee and sit down to watch it. It will probably be the 2o most constructive minutes of your day.
(Thanks Daveeeed for the link!)