Next generation e-learning platforms should support cooperative use of geographically distributed computing and educational resources as an aggregated environment to provide new levels of flexibility and extensibility. In this overall framework, our activity addresses the definition and implementation of advanced multimedia services for an aggregated Grid-based e-learning environment, as well as the design and experimentation of a content distribution and multimedia streaming infrastructure in light of edge device heterogeneity, mobility, content adaptation and scalability. In this paper we initially present the general objectives and requirements that we are taking into account in the development of a multimedia access service for an e-learning platform. Then we describe a partial system prototype which capitalizes upon traditional features of Grid computing like providing access to heterogeneous resources and services of different administrative domains in a transparent and secure way. Moreover, our system takes advantage of recent proposals by the Global Grid Forum (GGF) aiming at a standard for service-oriented architectures based on the concept of Grid Service.