There are many systems that provide users with an electronic identity (eID) to sign documents or authenticate to online services (e.g. governmental eIDs, OpenID). However, current solutions lack in providing proper techniques to use them as regular ID cards that digitally authenticate their holders to another physical person in the real world. We envision a fully mobile eID which provides such functionality in a privacy-preserving manner, fulfills requirements for governmental identities with high security demands (such as driver’s licenses, or passports) and can be used in the private domain (e.g. as loyalty cards). In this presentation, we discuss potential use cases and difficulties as well as present a general architecture for such a flexible and privacy-preserving mobile eID.