Recently, many national and international initiatives show an increasing interest in promoting distance education interventions by Universities. These directives aim at supporting students during their studies providing them with personalized solutions to their problems related not only to the fruition of on-line courses but also to orientation issues. In this paper we present a general architecture of an Embodied Conversational Agent (ECA) that has the main aim to assist students by providing personalized suggestions. This ECA represents the student interface in interacting with a Virtual University environment able to provide different types of services. In particular to support mobility, the ECA architecture has been conceived in order to run also on the student handheld device. The paper discusses the design and technical issues involved in developing this personal agent and the results of an evaluation study aiming at assessing the impact of conversational agents on the effectiveness of the interaction. (Contains 2 tables and 9 figures.)