At the end of the 20th century, access to information provided by the World Wide Web (WWW) is changing as never before. The fast availability of current medical literature and the availability of tools for easy access to information, as well as for the easy production of information, have confronted research physicians, scholars, and students with new kinds of problems, many of which concern us personally. Quality control, difficulty establishing basic citation components, lack of standard guidelines for citing, as well as the short lifetime of Internet addresses concern us deeply. Some of these problems could be solved by the concept of an "Online-Library of Medicine" presented in the following paper. Since, however, at the present time there are no good answers to the problems regarding citing Internet-based sources, a Web surfer must keep in his or her mind the motto "caveat lector" (let the reader beware) - or, rather, in the spirit of our time: click c@refully before you cite.