I found that it is impossible to override Back button action in TabActivity.
You should do it in the hosted activities
@Override public void onBackPressed() { Log.i("beshkin","[onBackPressed()] pressed"); getParent().moveTaskToBack(true); return; }
In this example, pressing Back button will put your app to back. Default behaviour will close it.
Note: you should put back you TabActivity, not hosted activity.