For anyone that hasn't seen it, netproject Ltd. has produced a document on behalf of the European Commission regarding migrating to Open Source products. The document was "intended for IT managers in public administrations within Europe," but it looks as though it would be of use to others as well. From the introduction: "The purpose of these guidelines is twofold: 1. To help Administrators decide whether a migration to OSS should be undertaken. 2. To describe in broad technical terms how such a migration could be carried out."
The complete document is at http://europa.eu.int/ISPO/ida/export/files/en/1618.pdf Mark Post