Web services are todays preferred vehicle for creating service-oriented architectures (SOA). Due to the boom of personal networked devices, the Web also found its way to the mobile space. This gives rise to device hosted mobile services that deliver functionality over a wireless network. There is potential to unite these services in a collaborative service space and exploit them as building blocks for distributed applications. This paper concentrates on a light-weight middleware layer to facilitate the integration, accessibility and orchestration of Web-based services in heterogeneous environments. Leveraging Web technology, this layer allows to interconnect serverless, peer-to-peer services deployed across federations of devices. We present its value in a ubiquitous application.