Sticking with today's naturally occuring theme of sustainability, I came across this great design/initiative over at the Canadian Design Resource. The idea is to get people thinking about the power their spending has and asking those tiny questions which, if asked by enough of us, can lead to major change.
I also find it very interesting that both the "depletist" campaign, and GiveMeaning.com (for the $5 philanthropist) have chosen $5 as a small/big enough denomination to effectively promote the "small can equal big" idea - it is just enough to make you think twice about things.
p.s. If anyone can find a website or more info regarding the "depletist" campaign, I'd be more than happy.