  Over the past decade quantum information theory has developed into a vigorous
field of research despite the fact that quantum information, as a precise
concept, is undefined. Indeed the very idea of viewing quantum states as
carriers of some kind of information (albeit unknowable in classical terms),
leads naturally to interesting questions that might otherwise never have been
asked, and corresponding new insights. We will discuss some illustrative
examples, including a strengthening of the well known no-cloning theorem
leading to a property of permanence for quantum information, and considerations
arising from information compression that reflect on fundamental issues.
