Are you engaged in academic publishing? It's helpful to know the various policies around copyright and self-archiving of different publishers. To learn about your rights as an author and the restrictions imposed by publishers, check out the RoMEO site, hosted by SHERPA.
Use the RoMEO site to find a summary of permissions that are normally given as part of each publisher's copyright transfer agreement.
If you need more information about publishing, copyright, or scholarly communication, visit the library's site at: http://www.lib.pdx.edu/services/scholarlycomm/scholcomm.htm. If you have questions, contact your subject librarian: http://library.pdx.edu/appointments.html.