If you're using the Duke LibX browser plugin, you can also use the right-click menu in your browser to authenticate as a Duke user via EZProxy directly from the page you're on. This doesn't work for all subscription resources, but is worth a try, especially if you've landed on something via a Google search (or some other way other than the library web site) and need to identify yourself as a Duke user in order to take advantage of the library's subscription.

More information about this (and other things LibX can do) are on the Duke LibX web page.