Every year at Usenix LISA it seems that there is a moment where someone says something that makes me want to jump up and shout, "OMG! Learning that just paid for my entire conference!"
It may be something an instructor says at a tutorial, a presenter says at a paper or Invited Talk. Often it is something you learn from the person you just happened to start chatting with while on line waiting for lunch.
If you have a "LISA Moment", I encourage you to tweet it with hashtag #lisa12 #moment or post it as a comment to this post.