Instant messaging has become a part of our daily live. Instant communication, either with a mobile device or with a computer based application, is an increasingly used form of communication. In this paper we analyze how current instant messaging can be extended to a new and more general form of what we call ‘ubiquitous presence systems’. We discuss how ubiquitous presence systems become a part of our daily live, extending the current systems, which only use states like ‘online’ and ‘away’, to location- and contextaware systems. We present the design space for ubiquitous presence systems together with a classification of those systems. We discuss information acquisition and also shortly address related privacy issues. We present an architecture for connecting arbitrary devices into the presence system, according to the vision of ubiquitous computing. We conclude the paper by presenting a fully working and deployed prototypical implementation following the developed archite...