DR. ODF: Using Python To Look Into ODF XML Files
Bob Sutor has been writing a series of articles in which he used Python to open up and examine an ODF word processor file (.odt). This kind of thing is essential for developing a complete understanding of the standard and how one can manipulate a file that conforms to the standard.
Apparently, he's planning one more installment, and then he thinks someone else can take up where he left off. At this point, he has not gotten into explicit "walking" of the XML.
If you are wanting to understand more of the internals of ODF, perhaps as a first step toward creating your own application that works with ODF, take a look at this series.