Stop Double Submits and then re-enable the button (when validation fails/etc)

nodoublesubmit.coffee

$ = jQuery

$.fn.extend
  nodoublesubmit: (options) ->
    settings =
      delay: 2000
      debug: false

    settings = $.extend settings, options

    log = (msg) ->
      console?.log msg if settings.debug

    return @each (i, el)->
      log "Setting up deplay for #{settings.delay} milliseconds"
      $el = ($ el)
      $el.submit -> 
        $el.find('input[type="submit"]').attr('disabled', 'disabled');
        callback = -> 
          log "Callback for Fired"
          $el.find('input[type="submit"]').removeAttr('disabled');
        setTimeout callback, settings.delay

If you're using jQuery 1.6.1+ you should probably be using .prop('disabled', true) and .prop('disabled', false) instead of .attr.