How can you setup odoo for Deferred Revenue?  For example you sell magazine subscription for $120 annual fee but you want to recognize $10 per month.  The $120 is credited unearned revenue and then moved to earned revenue of $10 per month.  There is a good article on setup for this in openbravo, but I didn't see how to set this up in odoo:  http://wiki.openbravo.com/wiki/How_to_manage_deferred_revenue_and_expenses