title: How to identify and make a link out of '@' in user comments like they do on Youtube
body: <p>I want to look into making functionality like Youtube has on their website when a user types in a comment and if they have something like '@username' the system recognizes the '@' sign and makes a link to the username's comments.  I'm developing using Rails 3 but any information regarding about the logic required for this feature would be appreciated, thanks.</p>
  
  <p>EDIT:  Additonal question:  Where's the best place to put the logic for this?  I would feel like the controller would be so if a client doesn't have javascript it'll still work.</p>