There are several ways for a librarian to be embedded in an online course. One of the simplest (from a technical standpoint) is to have the librarian enrolled as a student or guest lecturer in the courseware. Creating a "library" discussion folder or thread allows students to question the librarian directly and to receive responses within the courseware. The librarian can also post suggestions for particular assignments. All students have access to the discussion, so everyone gets the benefit of the answers and suggestions.
Administratively, however, this may cause some headaches. Enrolling an extra student is not always easy, depending on the courseware and on enrollment policies. There is also the problem of having an extra student showing up in the online gradebook. Guest lecturer status may not be easily accomodated by the software, and generally a librarian does not need full instructor access (test creation, access to grades, etc.)
It is also possible to embed links to the librarian (rather than the librarian herself). On the Distance Education Library Homepage I have a chat icon that links to an online chat service. This icon should show Online when I am signed into the service and Offline when I log out. Clicking on it will go to the Chatango chat service and display a Macromedia Flash chat box. If I am online, I get an alert that someone wants to chat. If I am offline, the option to leave a message is displayed. This button can be embedded in any HTML page, including WebCT pages, and students can contact me through this service. A full chat window can even be embedded in the web page, so that students don't even have to go to an outside web page. See the DE Librarian page for an example.
Using an outside link has the advantage of keeping the communication between the student and the librarian private. It helps with those "dumb questions" (that usually aren't as dumb as it feels, but still seem awkward in public).
It is also possible to embed RSS feeds in a webpage. Using an online bookmarking service, a librarian can create an RSS feed for a collection of resources, including websites, databases, even searches and specific articles within the databases. If the professor keeps the librarian updated on new assignments, new resources could be added regularly. LTA#44-Integrating RSS Feeds into your Course Management System gives a good description of how the technology works. For an example of using feeds in a website, see the Selected Internet Sites on the Physics Resource Guide (scroll down past Internet Megasites--sometimes the feeds load a little slowly, but they should come up one by one. If something doesn't load properly, refresh your browser.)
The chat links and the embedded feeds allow a librarian to have a presence within an online course without actually having to be enrolled in the course managment system. It's not as close a tie as actually having access to the course, but it's a good second choice if the administrative or technical arrangements can't be made.
If any of our online faculty would like to try any of these techniques, let me know!