Facebook added another layer to its Open Graph initiative this week, with the launch of so-called "action links" that allow users to interact with app-generated stories in a variety of new ways. These customizable links will now appear at the bottom of any Open Graph post that appears in a user's Timeline, News Feed, or Ticker, alongside the traditional "Like" and "Comment" options.

If you share a Foursquare check-in, for example, your friends will be able to bookmark that location directly from your timeline, using the app's new "Save this Place" action link. Similar functionality is now offered with posts generated by Fab.com's app, where users can "fave" items shared on their friends' Facebook pages.

These action links are aesthetically subtle, though they could offer some major benefits to companies and services looking to build a larger audience, or to enhance user engagement within Facebook's confines. Developers can find more detailed documentation here.