See if Doug Hellman's module of the week helps any
http://blog.doughellmann.com/2007/07/pymotw-subprocess.html  I plan on
asking him if we can include some of his examples in the Python 3000
docs.  Subprocess is new enough and gets enough questions on the forums
that I think we should be as detailed as possible and include more
examples than there are in other doc/tools examples.