  The information-thermodynamics link is revisited, going back to the analysis
of Szilard's engine. It is argued that instead of equivalence rather
complementarity of physical entropy and information theoretical one is a
correct concept. Famous Landauer's formula for a minimal cost of information
processing is replaced by a new one which takes into account accuracy and
stability of information encoding. Two recent experiments illustrating the
information-energy conversion are critically discussed.
