I recently saw a BizTalk demo that utilized the WSE adapter to authenticate against a web service using an X.509 certificate.  From what I saw this was purely a machine to machine authentication. 

The question I have is "Is it possible to dynamically pass my credentials i.e. X.509 cert, into a BizTalk orchestration such that such that the authentication against an external web service is done using MY credentials?"

I *think* what I am looking for (I am not a BizTalk guru so may be getting my terminology mixed up) is for an Orchestration to run under my security context so that everything that is done as part of that orchestration is done using my credentials... Is it possible?  Scott? Anyone?