In this paper we examine two approaches for the automatic personalization of speech controlled systems. Speech recognition may be significantly improved by continuous speaker adaptation if the speaker can be reliably tracked. We evaluate two approaches for speaker identification suitable to identify 5-10 recurring users even in adverse environments. Only a very limited amount of speaker specific data can be used for training. A standard speaker identification approach is extended by speaker specific speech recognition. Multiple recognitions of speaker identity and spoken text are avoided to reduce latencies and computational complexity. In comparison, the speech recognizer itself is used to decode spoken phrases and to identify the current speaker in a single step. The latter approach is advantageous for applications which have to be performed on embedded devices, e.g. speech controlled navigation in automobiles. Both approaches were evaluated on a subset of the SPEECON database which represents realistic command and control scenarios for in-car applications.