application.js

$('.submittable').live('change', function() {
  $(this).parents('form:first').submit();
});

index.html.erb

<%= form_for @thing, :remote => true do |f| %>
  <%= f.check_box 'checked', :class => 'submittable' %> 
  <%= f.label :checked %>
  <%= thing.name %>
<% end %>

tickets_controller.rb

class ThingController < ApplicationController
  def update
    @thing = Thing.find params[:id]
    @thing.update_attributes params[:thing]
  end
end

update.js.erb

// we could highlight the checkbox to show it's been clicked:
$('#thing').css("color","yellow");

// or add the updated thing to a list:
$('#things').prepend('<%=escape_javascript render(@thing) %>');