Membership Login Information Dilemma

I would try it like this:

  1. set up a collection with a unique ref to every user, either being userid or email
  2. set up a signin/join page that needs Membership
  3. this will trigger the login/join dialog
  4. check the db if this user exists
  5. if so, redirect him to page x
  6. if not, redirect to page y (or .show() all hidden elements on that very page if you don´t want a redirect)
  7. on page y, show a form with anything you want them to fill out, write it to the db with either his userid or email
  8. next time, from 3 on he will go to page x because he already exists