The scientific community has begun using new information and communication technologies to increase the efficiency with which publications are disseminated. The trend is most marked in some areas of physics, where research papers are first circulated in the form of electronic unrefereed preprints through a service known as arXiv. In the first half of this paper, I explain how arXiv works, and describe the conceptual backstage and its growing influence. I will look at the motives behind the developing technologies and focus on the views of promoters and makers of the system. In the second half of the paper, I look at the eventual fate of papers initially circulated with arXiv. While it is argued that preprints are sufficient for the everyday scientific practice, nearly every paper in some specialities finds its way into formally peer-reviewed journals and proceedings. I argue that the continuation of traditional publication practices, in spite of their costs and inefficiencies when compared with arXiv, suggests that formally certified publication still has important roles. Certified publication verifies the relevance of scientific work and establishes professional credentials in the outer rings of the community, whose members are not sufficiently embedded in esoteric networks to make appropriate judgements on the basis of reading papers in isolation, or even through consultation.