The challenging context of Ambient Assisted Living (AAL) demands for a service-oriented technological shift in the field of ubiquitous computing. Recently, novel paradigms have been proposed, most of them envisioning arbitrary pairs of peer application entities communicating and providing services directly with each other and to users. In order to enforce these paradigms even to systems which include devices with limited processing and storage resources, lightweight middleware components are required. JXTA-SOAP, a portable software component supporting peer-to-peer sharing of Web Services, is a suitable solution. We illustrate its features and a possible deployment to enable AAL services. Key words: ubiquitous computing, ambient assisted living, services, peer-to-peer