Wireless hotspots and broadband coverage are permeating the globe giving rise to interesting spontaneous networking scenarios. The discovery and delivery of the most relevant and suitable services in a spontaneous network is a problem of paramount importance. In this paper, we propose an architecture that can support context-aware service discovery and delivery for resource-constrained mobile devices. At the heart of the architecture is the ..Jini proxy which mediates the discovery and delivery processes. Its delivery subsystem provides thin-client based adaptation for fat service delivery that does not fit into thin client devices. To demonstrate its effectiveness, we developed a proof-of-concept prototype, focusing first on J2ME smartphones.