Foreword While Mobile Communications continues to be a very successful industry, the number of s- cessful mobile applications still seems to be limited. Certainly, mobile voice and email are attractive to more and more customers. However especially during the boom around the UMTS license auctions much more fancy mobile applications were discussed, sometimes seen implemented – but never really widely used. Often high costs, especially compared to the costs of the “fixed” Internet, were given as r- sons for this. But considering the prices businesses, and more and more private people, pay for mobile voice and email connectivity, other reasons must exist for the reluctance to use mobile applications. One reason seems to be that quite a few people are not convinced, that mobile access or receiving information on a mobile device adds value. More formally spe- ing, usefulness or a relative advantage are not perceived, especially when the ones receiving the information are busy decision makers, who have other things to do. Especially when c- fronted with the still existing weaknesses of mobile devices, e. g. their limited I/O-capabilities they may see mobile work as mobile stress with no sustainable use.