The Dudley Observeratory have become much more active in promoting Astronomy in recent years by hosting public outreach event and more recently, the yearly lecture series which I find extremely informative. I've assisted at some of their programs and am amazed at the interest and results they are getting. They are definitely an asset in this neck of the woods.
A classic example of a non-profit that makes their mission rather accessible to the community with very little funding. Great programs for people interested in the topic, for students, for teachers, etc.