Right - what I had in mind was perhaps capturing the username/password as entered for a month or so and then migrating that to the new registration app, this way the most active users wouldn't have a password reset, and the transition would be seamless for most users.
I think I can see you shaking your head "no, not gonna happen", but I thought I'd ask perhaps you can point out where (ASP page and lines/variables) and what I can use to pick up this data (and perhaps save it to a text file outside of the public www folder) so I can use it later.