Doorbell heterogeneity QuickTopic http://www.quicktopic.com/25/H/q2XWk8iDngG7 http://www.quicktopic.com/25/H/q2XWk8iDngG7/p. 2004-01-29T17:35Z http://www.quicktopic.com/25/H/q2XWk8iDngG7/m