Dennis Crowley, co-founder of location based social network Foursquare, told attendees of the Picnic conference in Amsterdam today that the company has built a feature that recommends new locations users ought to visit, based on their past activity, their to-do lists and what's popular at the moment. The system is being tested internally by Foursquare staff and Crowley hopes that Foursquare user data will be used by outside developers to build even more kinds of recommendation services. Recommendations, generally, are like searches you hadn't thought yet to perform - in Foursquare they could be a great way to foster new experiences for users and additional activity for businesses.

Crowley's talk was first reported by watchdog blog About Foursquare, where a video of the 20 minute presentation from Picnic can be found.

Crowley also discussed prospective features further in the future, including passive location tracking and push notifications of nearby recommendations (recommendation + geofencing), and identification of topic experts based on check-in behavior.

"Users would be awarded experience points as a sushi expert or skiing expert based on their checkins in those categories, for example," About Foursquare writes. "Their recommendations could carry more weight and be used to suggest places other users should visit."

Data about real-world behavior, combined with social connections, geographic locations, annotations of locations via tips and to-do items - that's a potent mix for possible innovations in any number of features for this service, or services built on top of it.

Recommendations: High Risk, High Reward

Recommendation is low-hanging fruit, but whereas recommendation of online content from other services is relatively low-impact, recommendations that a person set foot in a particular venue probably carries a lot more weight. For better and for worse. If Foursquare recommendations are unsuccessful or feel counter-intuitive to users, users may be very unhappy about that.

No doubt the company is testing the feature thoroughly among its New York City staff, but whether recommendations can succeed outside a venue-dense city with intense support for an otherwise small social network remains to be seen.

Foursquare claims to have approximately 3 million users, neither the biggest (that's Facebook) nor the smallest player in the location based social networking market. It may be the most consistently innovative competitor in this space, though.

In addition to recommendations, the company has long talked about incentivization of real-world behavior. Today, for example, Foursquare announced a partnership with CNN, which will give a "healthy eater" badge to anyone who checks-in at one of ten thousand farmers markets. It's unclear whether a dorky apple badge with CNN emblazoned on it is going to incentivize anyone to do anything - but it's a start and an interesting idea.

Imagine checking in at a farmer's market, then later receiving recommendations to restaurants that cook with locally-sourced food when you check-in nearby. It's got to be just a matter of time before big companies like McDonald's start incentivizing fun and Happy Meals lest we all get too many farmers market recommendations.