Today's high performance computing systems are typically managed and operated by individual organizations in private. Computing demand is fluctuating, however, resulting in periods where dedicated resources are either underutilized or overloaded. A cloud-based Infrastructure-as-a-Service (IaaS) approach for high performance computing applications promises cost savings and more flexibility. In this model virtualized and elastic resources are utilized on-demand from large cloud computing service providers to construct virtual clusters exactly matching a customer's specific requirements. This paper gives an overview on the current state of high performance cloud computing technology and we describe the underlying virtualization techniques and management methods. Furthermore, we present a novel approach to use high speed cluster interconnects like InfiniBand in a high performance cloud computing environment.