Change own phone number in ICS I've change the SIM in my Galaxy-Nexus-S. Under Settings -&gt; About phone -&gt; Status there still is the old phone number and I cannot manage to change it.

I've seen this answer which is outdated. The menu option Own numbers discribed in the answer is not there in ICS.

The navigation terms might be called differently, as I manually translated the names from German.
In previous versions of Android (mine is 2.3.7) you can set this setting in the Additional call settings. In Android 4.0 the Additional call settings screen is located here:

Open the Phone app -> [Menu] -> Settings -> Additional settings.

I have not verified this on a physical device yet.