Popular Firefox addon Read It Later has introduced an updated version of their plugin which adds new functionality to Google Reader. The updated Read It Later extension adds a Greasemonkey-esque feature to your Google Reader feed list that places a check mark next to your feed items to the right of the star. As you go through your feeds, the posts you check will be automatically added to your reading list - the saved list of items you can access at anytime at readitlaterlist.com. With the extension's included offline functionality, you can also queue up a number of articles to read when you know you're going to be away from the net - like when you're on a plane trip, for example.
More info: Read It Later