Not a preset mod. It's been discussed here a bunch, and I've implimented it on alot of sites. But everything's so site specific as to what fields they wanted included, it's not something I've been able to write up.
You basically add the fields to the new user page templates, then have adduser.php perform the necessary checks (same as in changebasic.php) and then add the stuff to the database. But what you need to do do has to do alot with what fields you want to collect.
