updated the README to reflect success callback changes

README.rdoc

@@ -95,6 +95,13 @@ In case you need to trigger a method call after a successful transition you can
     transitions :to => :discontinued, :from => [:available, :out_of_stock]
   end
 
+In addition to just specify the method name on the record as a symbol you can pass a lambda to
+perfom some more complex success callbacks:
+
+  event :discontinue, :success => lambda { |order) AdminNotifier.notify_about_discontinued_order(order) } do
+    transitions :to => :discontinued, :from => [:available, :out_of_stock]
+  end
+
 == Timestamps
 
 If you'd like to note the time of a state change, Transitions comes with timestamps free!