In my previous job, I was responsible for promoting civil society activity on the United Nations Millennium Development Goals, a set of development targets agreed to by the governments of the world in 2000 at the UN General Assembly. It’s an important list of commitments to combat some of worst social ills — including poverty, HIV/AIDS, slums, and evironmental destruction.
From September 16 to October 17, people are "standing up against poverty" in demonstrations around the world from Armenia to Senegal to the US of A.
Even in the virtual world, there is a digital equivalent to these civic mobilizations, with Second Life residents showing their support for the Millennium Goals by wearing white wrist bands and tee-shirts and posing in a special "stand up" pose from October 15-16. This is my avatar wearing one of the tees above.
There are hundreds of kiosks in-world where you get these tees and wrists bands for free (this one is in Midnight City.)
More on this effort in the SL Insider and Sl explorers sites.