I followed some walk-throughs to create a web application using forms
authentication.  All is well.  Basically, what happens is the user requests
a page from the app, the app redirects the user to the logon page, they log
in, the page creates an encrypted FormsAuthenticationTicket and attaches it
to an HttpCookie, then redirects the user back to the original request page.
Now, on when the client requests this page that they are redirected too, in
Application_AuthenticateRequest, we fetch and decrypt the
FormsAuthenticationTicket and create a FormsIdentity and a GenericPrincipal
object from the ticket.

I created a standard, default web service (kept the HelloWorld web method)
and am trying to figure out how to pass the credentials from the web
application to the web service. Optimally, I would like to do this without
passing them as a parameter to every web method in the web service.  Does
anyone have any tips, tricks, or other internet resources they can redirect
me to in order for me to accomplish my goal?

Thanks,
Mythran