I am looking for a solution that will allow users to share the same document across multiple document libraries. No matter the location of the document, if the user edits the document or its metadata, the changes should be reflected in all of the document's locations. I am basically looking for an alternative to the "Link to a document" functionality provided by MOSS 2007. We are trying to get away from it as it is too difficult to maintain all of the links as documents are deleted/moved/renamed, etc. If there is a built-in method of doing this, that would (of course) be preferred. Thanks in advance!
First off, there is no way to accomplish exactly what you describe. SharePoint 2010 brings a document ID feature to the SharePoint environment which allows you to move documents to different locations in the site collection without breaking links. If you standardize on the document ID links in your organization, you can be sure that everyone is seeing the same metadata and document. This does not help your desire to have the document in multiple locations in SharePoint.