One of the common questions asked following my posts about Google Analytics was “How can I track the traffic to external links without adding the onClick code to each and every link?”
With a bit of searching I found a script that you can place in the header file at the top of each of your pages (you might need to edit the templates if you run WordPress). The script tracks clicks to external links and reports them in Google Analytics. You need to filter the results in the “Top Content” tab to show page views for “outgoinglink” to get the pages to show.
Let me know how it works out for you.