I've really enjoyed this presentation. Thanks for sharing

Implementation of "tail -f filename" in Python given as example. (slightly altered)

  def follow(filename):
       f = open(filename)
       f.seek(0,2)
       while True:
           line = f.readline()
           if not line:
               continue
           yield line

  for new_line in follow('/tmp/test.file'):
       print new_line

This is so cool.