While updating my apps to Kitkat, I just wanted to give them a gorgeous look on KitKat using the Translucent property:
Translucent system bars
All of the answers extend the ActionBar either programmatically or from layout: what this means is that when the app gets launched or recreated the system will look for the theme (which isn't aware of the fix) and show a VERY UGLY status bar coloured with whatever is the window background...!
I have created an example of how to do it using the theme only:
https://github.com/Takhion/android-extendedactionbar
I hope it will be useful for someone :)