I just came across a Flex framework class I was previously unaware of.  It’s the AsyncResponder class and has a nifty extra parameter in addition to the ‘result’ and ‘fault’ parameters of the normal Responder class.  The third parameter allows you to pass-through data in the form of a token object.  This could definitely come in handy when trying to use the Command pattern if you don’t want lingering commands. For more info, check the link below. AsyncResponder Flex Docs