Computers are indispensable to providing reference desk assistance. Yet users have a limited view of the librarianís screen or no view at all. They are relegated to passive interaction with the librarian. In March 2004 co-browsing was introduced at the reference desk at the Seton Hall University Library and subsequently in three other libraries. Co-browsing enables users to actively engage in searches with the guidance of a librarian. In co-browsing the user has a separate monitor, keyboard, and mouse all interconnected to the librarianís computer. This enables both librarian and user to input to the computer and to see the otherís input. Installation of co-browsing is inexpensive, quick, and not difficult. With co- user engages with the librarian in searching. As a consequence the focus of the reference transaction shifts from librarian to the user. It appears to increase the satisfaction of users and to be an effective learning tool. We propose that co-browsing become the standard mode in reference service at the reference desk, and in virtual reference. There is potential application of co-browsing in other one-to-one environments utilizing computers such as in IT centers. Experimentation with co-browsing at the reference desk is recent, and it is installed in only a few locations. Research on user satisfaction and learning outcomes is in order.