Question : How to change Document Ownership in SharePoint

How can I manage to change the document ownership in Sharepoint?

Answer : How to change Document Ownership in SharePoint

Also, you might want to create a Custom Field called "Responsible" or something like that and make the field a lookup field for the users in your Active Directory.  The only thing is, everytime someone modifies the document, they will have to go an modify the "Responsible" field for that document.  I know it is a 2 step process but maybe that will work.