In the upcoming world of Pervasive Computing, users are accessing information sources by a huge variety of mobile devices featuring heterogeneous capabilities. Those devices are attached to the Internet by various communication systems offering different quality of service. The key to meet the demands in this heterogeneous environment is the adaptation of contents to the capabilities of the devices and communication systems. However, content adaptation interferes with the effectiveness of web caching applied in the World Wide Web to improve the performance by avoiding redundant data transfers. Leveraging the advantages of web caching even in the world of Pervasive Computing is the subject of this paper. We outline and discuss an approach that joins the concepts of web caching and content adaptation in a uniform scheme. It is based on hierarchical proxies that do not only cache web objects but even cooperate to adapt the objects to the requirements of the particular clients when they travel down the hierarchy. By our approach the interference between content adaptation and web caching is avoided resulting in improved caching efficiency.