BSCW [8] and Groove [10] have become the two defacto standards for collaboration over the Internet. They offer a wealth of functionalities, support a variety of possible collaboration styles, and are applied frequently in research and business projects. While being useful and powerful for standard scenarios, they suffer from some problematic aspects if support for distributed ad-hoc and mobile collaboration is needed. Both are centralized systems which require the setup and maintenance of a server. Setting up such an infrastructure for short-term and ad-hoc collaboration of mobile users is not feasible since it requires the infrastructure to be in place and configured a-priori, which is costly in terms of hardware, software, and time. Thus they are not very adequate for flexible, short term collaborations, a genuine building block of many light-weight distributed mobile collaboration scenarios. In this paper we discuss how P2P approaches could be applied to remedy these shortcomings...