As cap10morgan noted in a recent blog, non-profits and open source solutions are a natural partnership. CiviCRM has been a fabulous gift to the organization that I lead, Trinity Episcopal Church. It allowed us to move from a FileMaker database accessible only to our office staff to a robust solution accessible to most of our membership. (We constantly remind ourselves that not everyone's online!) We are still using a FileMaker/CiviCRM hybrid solution however and CiviPledge is our roadblock.