Inter-application communication? Or something??

[Dave Wengier]

I have an application running that uses Forms Authentication, and its login page is in another application (standard log in page used for single-sign-on amongst a few different web apps). What i'd love to do is to have some way to specify what should be in this login page, depending on which application redirected to it. Obviously Session or Cookie variables would work, but with Forms Authentication, the redirection happens before any of my code gets executed (there isnt even a Referrer I can read and do something cool with). Any advice would be appreciated.