jQuery plugin for making textareas auto-exapand. Based on article at http://www.alistapart.com/articles/expanding-text-areas-made-elegant/

makeExpandingArea.coffee

$ = jQuery                                                                                                          
                                                                                                                    
$.fn.makeExpandingArea = () ->                                                                                      
  @.each ->                                                                                                         
    container = $(@)                                                                                                
    area = container.find('textarea')                                                                               
    span = container.find('span')                                                                                   
    area.on 'input', ->                                                                                             
      span.text(area.val())                                                                                         
    span.text(area.val())                                                                                           
                                                                                                                    
    # Enable extra CSS                                                                                              
    container.addClass('active')