WordPress.org

Author: Satollo

Using the Google Analytics functionalities (you need to have a Google Analytics account and the Google Analytics code installed in your blog) the plugin add a little javascript code the track all the clicks on links going outside your site.

It can also force the outbound links open in a new window, without change a byte in your theme or posts.

More here: http://www.satollo.net/plugins/outbound-links.