The .org works well for charities and political issues. If looking for end users I would maybe try to find a charity which you could possibly link with the domain name. Charities won't pay the most but if it links to a fundraising or political campaign they are running, you might get something. I had a quick search and there is a campaign going on at the moment to Save the City Park Golf Course in Denver. Maybe worth seeing if they want to pick up the domain from you!