Ad-hoc networks enable mobile devices to communicate without any fixed infrastructure. While reliable multicasting has been identified as a key application in this context, we analyze different aspects of ad-hoc networks and their impact on application-layer multicast. As a result, we propose our technique of local broadcast-clustering, making use of the wireless medium's broadcast capability. We further describe a simple congestion control as well as a technique for avoiding an overlay's routing inconsistencies and thus for stabilizing the delivery of multicast data.