To quote Kaj_Sotala's original thread:

We have plenty of effective altruists around the world, each doing something to make the world a better place. If we all work separately and don't report of our work, most of our efforts will go unnoticed by others in the community, who could otherwise provide encouragement or suggestions, or be inspired by our work.

If you've recently carried out some effective altruist activity, come here and let us know about it.