title: Good examples of applications using Message Queues
body: <p>I would like to learn more about programming messaging applications and using message queues. Things like qpid, Amazon Queues, etc. Can you point me to some apps (preferably C++, open source if possible) so I can learn more.</p>
  
  <p>Also, can you tell me the general guidelines one would use to decide whether ot not to use message queues. I am interesting in leanring about this just for the 'coolness' factor but I think it might be beneficial for me in the future.</p>