Today at Inside Social Apps 2011, Martin Essl, part of Strategic Software Partner Management at Sony Ericsson, announced that his company will preload the Android devices it makes with a Facebook app and single sign-on [updated: that appears when users first turn on the phone]. 

This is an industry first for a device maker, and will encourage Android developers to use Facebook for social features because users won’t have to type in their email and password to try new social apps.

When users unbox their new Sony Ericsson Android device, they’ll be asked to log in to Facebook as part of the set up process. Then, once users download third-party Facebook-integrated applications, they won’t need to login, but just authorize thanks to single sign-on. “Facebook is the primary social network provider” said Essl.

Facebook introduced single-sign on in December to reduce the friction in trying Facebook-integrated mobile apps. The system allows apps to borrow the Facebook login authentication token from the device’s primary Facebook app, like Facebook for Android. The system encourages application experimentation amongst users.

Essl acknowledges that “Facebook isn’t strong in every market, but we do see in Sony Ericsson’s markets that Facebook is usually the primary network.” Preloading devices with Facebook will ease user acquisition for third-party Facebook-integrated apps, making Sony Ericsson, Android, and Facebook more attractive to developers.

Sony Ericsson will also utilize the social graph to power native functions of its devices. Users can already pre-populate their phone book with contact information of their Facebook friends. These additional integrations will be revealed in the near future.

The preloading of its app is a win for Facebook as well. Sony Ericsson sold nine million Android devices last year. Similar or better numbers in 2011 will help Facebook boost its mobile user count well above the currently listed 200 million.