Hello,
Since IPB3 is using the new OpenID program, I would like to suggest that IPS maybe use Facebook Connect as well. Millions of people use Facebook and the amount of people that would be able to register using FB Connect FAR outnumbers those using Open ID http://developers.facebook.com/connect.php
This would certainly be a feature that could set IPB apart from it's competition. It can also probably be set up so that new users have their profile picture as their avatar!
-Tom