I’ve been aware of this plugin for a few years now and have been hoping someone would pick up the development of it, especially to make it work with WPMU (now known as WP 3.0 with Multi-Site enabled).
I actually just purchased a similar plugin after talking with their live support, but it’s not working as expected with either my WPMU 2.9.2 of my WPMS 3.0 installations. I am working with them to try and figure out what the issue is and I’ll post back when I learn more.
Having a plugin that allows for relatively easy customization of the registration fields and profile fields is the holy grail of WordPress plugins as far as I’m concerned. I’ll gladly fork over cold hard cash if I could find one that worked out of the box and was supported.
The rumor is that Gravity Forms might try and build in that functionality in the future, but who knows?
By the way, the plugin I just purchased was:
https://tribulant.com/plugins/view/7/wordpress-custom-fields-plugin
Keep in mind that this is not on the WP plugin repository but there is a different plugin with the same name. This causes an issue with the automatic upgrade script because it tells you there’s an update for the plugin, but it’s really an update for the OTHER plugin.
Maybe I’ll start an initiative to gather a community of WP users to fund the development of a kickass registration/profile fields plugin…hmmm…