A test application on Facebook suggests the social network may be working with Twitter on Open Graph integration that will share more of a user’s Twitter activity on Facebook Timeline.

The test app, under the alias of “Sports Betting,” uses the Open Graph action “follow.” Although other services allow following, it is primarily associated with Twitter, and Twitter is one of the few that hasn’t already released a Timeline app. Quora launched an Open Graph integration using “follow” last month. We’ve previously suggested that Twitter could benefit by integrating with Open Graph. Social sites like Pinterest, Path, Foursquare and others already do and are seeing lifts in users, referrals and sharing activity.

The Sports Betting app is being tested by Facebook product manager Austin Haugen who focuses on Timeline applications. Interestingly, Haugen used the same app to test the “listen” action for Rdio a few days before Facebook announced Open Graph apps at f8 last year. If Facebook were helping Twitter with an integration, Haugen would likely be involved, however it’s possible the “follow” action is being tested for another service, not Twitter.

[Update 6/27/12: The "follow" action we saw being tested could related to a new Open Graph built-in follow action announced today that makes it easier for people to keep tabs on the stories people tell from within an app in their News Feed, Timeline and through the notifications channel.]

In tests this week, Haugen indicated that he “followed” a number of people. Some of those people are Open Graph objects with the name “Ahimel,” which is engineering manager Alex Himel’s username for both Facebook and Twitter. These objects link off-Facebook to austinhaugen.com/opengraph/profile, which brings up a blank page. Other people that Haugen has followed using the test app include Mark Zuckerberg and a dummy profile, “Helen Diijffbgj Te.” These link to Facebook profiles.

Twitter already has a Facebook integration that lets users post tweets to their profiles and friends’ News Feeds, but it does not use the new model of sharing to Timeline, Ticker and News Feed via Open Graph actions. It also does not share retweets or @replies. An Open Graph app could help users easily share their tweets and other actions, like following or favoriting, and organize them in a box on Timeline and in News Feed aggregations. Third-party app, Twittus, already does this so it is likely that Twitter would want to have its own official version.

Twitter recently made changes to its existing cross-posting feature so that tweets shared on Facebook include more rich media, so the company is clearly interested in optimizing how its content appears on Facebook.

[Update 7/1/12: Facebook's Graph API Explorer suggests that Twitter has already defined a number of Open Graph actions, including "follow," "post" and "retweet." This is strong evidence that the company is working on a deeper Facebook integration.]

Facebook and Twitter did not offer comment on a potential partnership involving Open Graph.