I want to use Survey Project to gather requirements via questionnaires.  But one user may not have all the answers.  I want to do something like:

Invite UserA to take the survey.

UserA fills in all he knows, saves the answers, notes the resume code, and passed it to UserB

UserB starts the survey, enters the resume code, and fills in some more information.

But I want to be able look later and see that UserA and UserB both contributed. Not on a question by question basis but for a set of responses. It seems only the last e-mail address is stored in the database.

I'm considering creating a large text field that users can enter their address into but I'd like at least the first user to have their e-mail address prefilled. I know I can use ##...##, @@...@@, etc. but I don't know that any of those have the user e-mail. Any thoughts on where I can get the user e-mail and use it as a default value?  Does SP fill any session variables like this?  Is there a list somewhere?