I am one of the founders of NGO Post. To comment on your point “it is not easy to involve others to join, when everybody is already involved in so many on-line networks” from our experience – Indeed, getting people involved has been our biggest challenge. We have done a bit of viral publicity (more aggressive plans on the way) and see quite a few hits from all over the world. But it is difficult to have those users keep coming back and more importantly submit and vote on stories rather than just reading and going away. This is so needed for web2.0 to work!

Pligg did greatly ease getting the site up – although its features are limited and we have had to do a few tweaks. Currently seeking funding to develop the extensive features which will make it more user-friendly and resourceful and lead us to the ideal you talk about here:

http://www.crisscrossed.net/2008/03/19/ngo20-the-end-of-the-organization-1/