We like Actionbar Sherlock. It just works. Essentially it is a backport of the Android actionbar to earlier operating systems, however it follows the same methods as the actual actionbar. Further – the code works fine on actionbar supporting devices (3.0+). Lots of people however seem to have trouble getting started therefore we produced the following tutorial in video form.
It was also a great excuse to create a YouTube channel, which incidentally can be found at http://www.youtube.com/user/WisemanDesigns