grabs timeline tweets off twitter and puts it in a android listview. This is an example of how a fragment can be used to embed a asynchTask. A taskFragment class is created to do background heavy work against twitter.com. The taskFragment retains its instance thus on android orientation change the network call is persisted and does not begin again. After the fragment has completed the task it removes itself from the fragmentManager. so its totally self maintained.
Classes that want use this taskFragment need to implement the interface i made called TaskCallbacks otherwise it throws a class cast exception.I'll design a solo implementation of this taskFragment later to add to your design.