Today we released Places, a new way for people on Facebook to share where they are, see where their friends have checked in, and discover interesting places nearby. As part of the rollout, we’re making Places available to developers via the Graph API, so you can integrate location features into your own mobile applications, websites, and applications on Facebook.

Once you are granted user permission, you can access a user and their friends’ check ins on their behalf. More information on the Graph API can be found here.

Through the Graph API, developers can surface this data in their applications to create a variety of social experiences, such as:

• A travel application that gives people the ability to see which of their friends have already been to the place they are visiting
• A conference application that makes it easy for attendees to find colleagues and connect with them
• An event application that enables attendees to see where their friends are at a concert

In the coming months, we will offer additional location features through the Graph API and the Open Graph protocol, including the ability to check in with Facebook through your application and discover places nearby. We’re working with an initial set of partners including Gowalla, foursquare, Yelp and Booyah’s InCrowd to enable users to share check-ins on Facebook. This new functionality will launch in partner applications soon.

It’s important to remember that all access to location information through the Graph API respects a user’s privacy controls, which can be viewed and changed on Facebook.com or m.facebook.com. When a person installs an application that needs their location to provide a relevant experience, the application must request access through Facebook’s clearly labeled permissions dialog. Developers cannot share location information without a user’s express permission, and every user has control over what their friends can share via the API.

We look forward to seeing how you incorporate Places with your applications to help people share their location with friends.

Ben, a Places engineer, recently checked in at Año Nuevo State Park to watch the elephant seals’ annual molting ritual.

At Facebook, we are huge believers in what a small dedicated team with a unique perspective can accomplish. We’ve already seen how a group of startups who built social interactions into the core of their product experience have completely changed how people play games online, and we think what has happened in the games market is just the beginning.

As part of our ongoing efforts to engage with developers, we’re partnering with Y Combinator — an early stage venture firm — to help encourage and support startups who want to build their business around a social experience. Y Combinator has already invested in companies at the forefront of new social experiences such as Scribd, Justin.tv and Divvyshot, a photo company we recently acquired.

We’ll provide product, technical and design resources to support new Y Combinator companies interested in working with us to build deeply social products, whether a website or an application on Facebook.com. These companies will have priority access to our technologies and programs such as Facebook Credits, Instant Personalization and upcoming beta features. Y Combinator will be publishing a “Request for Startup” focused on social startups and is now looking for interested entrepreneurs for their winter 2011 funding cycle.

In the near future, we think it will be hard to imagine a web experience that is not personalized. Startups that can build in these interactions from the beginning — not simply add them to existing products — will be the examples of transformative social experiences others will follow.

Carl, who leads the Platform product team, is excited to see some great new social applications.