Somebody, sometime, somewhere, something [ubiquitous computing]

The success of the Web and of portable devices has made popular the idea that any information could be made available to anybody, anytime, and anywhere. Other paradigms are taking off within the ubiquitous computing solutions. This paper identifies some of these paradigms, focusing on the more innovative ones in terms of information services. In particular, broadcast-based and location-based services are introduced. Further, it discusses user profiles and contexts, two essential components for modern services.