The goal of Open Access (OA) is to grant anyone, anywhere and anytime free access to the results of scientific research. The High-Energy Physics (HEP) community has pioneered OA with its “pre-print culture”: the mass mailing, first, and the online posting, later, of preliminary versions of its articles. After almost half a century of widespread dissemination of pre-prints, the time is ripe for the HEP community to explore OA publishing. Among other possible models, a sponsoring consortium appears as the most viable option for a transition of HEP peer-reviewed literature to OA. A Sponsoring Consortium for Open Access Publishing in Particle Physics (SCOAP3) is proposed as a central body which would remunerate publishers for the peer-review service, effectively replacing the “reader-pays” model of traditional subscriptions with an “author-side” funding. Funding to SCOAP3 would come from HEP funding agencies and library consortia through a re-direction of subscriptions. This model is discussed in details together with a quantitative description of the HEP publishing landscape leading to a practical proposal for a seamless transition of HEP peer-reviewed literature to OA publishing.