PowenKo > Android > UI > Action Bar > Customizing the Action Bar
http://android-developers.blogspot.com/2011/04/customizing-action-bar.html
iOS, Android, Unity3D Education blog,
http://android-developers.blogspot.com/2011/04/customizing-action-bar.html
sample code: TutorialActionBarNavigationActivity
sample code: TutorialActionBarActivity