According to Jared Diamond's recent NY Times article, "we (Westerners) will soon have to lower our consumption rates, because our present rates are unsustainable." He goes on to say that "real sacrifices wouldn't be required" because "much American consumption is wasteful and contributes little or nothing to quality of life."
I have to disagree about the sacrifice part: conserving resources and curbing our carbon emissions will probably require a bigger sacrifice than most of us are willing to admit. Switching our light bulbs and lowering our thermostats by 2 degrees won't do it.
But I do think there are lots of areas of waste in our consumption that could be eliminated very easily.
One place to start would be packaging: we don't actually want it, but we bring it home with our purchaces and often put it right in the trash. Depending on what you buy, as much as 90% of the volume might be trash. (If you could buy that memory card for your camera without the giant plastic clamshell it comes in, would that be a painful sacrifice?)
Here is another area of wasteful consumption we could work on: