Pertti Huuskonen from Nokia presented his keynote at Percom in Mannheim. I worked with Pertti in 1999 on a European Project TEA - creating context-aware phones .
After telling us about CERN and some achievements in physics he raised the issue that an essential skill of humans is that they are context-aware. Basically culture is context-awareness - learning how to appropriately behave in life is essential to be accepted. We do this by looking at other people and by learning how how they act and how others react. "Knowing how to behave" we become fit for social life and this questions the notion of intuitive use as it seems that most of it is learned or copied from others.
He gave a nice overview of how we can context-awareness is useful. One very simple example he showed is that people typically create context at the start of a phone call.
One example of a future to come may be ubiquitous spam - where context may be the enabler but also the enabler for blogging adverts. He also showed the potential of context in the large, see Nokoscope. His keynote was refreshing - and as clearly visible he has a good sense of humor ;-)
 Schmidt, A., Aidoo, K. A., Takaluoma, A., Tuomela, U., Laerhoven, K. V., and Velde, W. V. 1999. Advanced Interaction in Context. In Proceedings of the 1st international Symposium on Handheld and Ubiquitous Computing (Karlsruhe, Germany, September 27 - 29, 1999). H. Gellersen, Ed. Lecture Notes In Computer Science, vol. 1707. Springer-Verlag, London, 89-101.