The current issue of Computers in Libraries introduced me to an open source chat reference software called RAKIM. The article, Implementing RAKIM Open Source Chat Reference Software, describes how librarians at Midlands Technical College decided to try this package (mostly because it's free), and their impressions of its capabilities and limitations. A couple of the interesting features that caught my eye include the ability for librarians to have their own or shared bookmarks, and their own or shared scripts they can push to the patron. If a patron logs in and no librarian is available, s/he will be routed to the e-mail reference page. The software allows the librarian to push a page to the remote user, but does not allow co-browsing. The other drawback is that it does require a little technical know-how to get up and running, requiring Linux, Apache, MySQL, and PHP. If you're already comfortable with LAMP, you might want to give this a try. There are some screenshots available as well.
Here's a direct link to the article for those of you with Academic Search Premier.