As a contributor to the EthicsCORE site, I have to admit to a bit of bias, but I always find something new when I take time to browse the latest additions to the web site. Funded through an NSF grant, its mission is to "bring together information on best practices in research, ethics instruction and responding to ethical problems that arise in research and professional life." The project is coming out of the University of Illinois Urbana-Champaign's new National Center for Professional and Research Ethics, and is inviting other ethics centers and scholars in the field of professional ethics to contribute to the project.
The site, which is still under development, includes the ability to do multiple kinds of literature searches in the field of professional ethics, browse through its collection of teaching materials, and allows you to get full-text access to just about any article you can find, including full access to the Encyclopedia of Science, Technology and Ethics. There are numerous other features that are still in the works, including an online journal, so be sure to bookmark this site and check back regularly.