I'm currently working on launching a venture website at strongislandgamers.li/index.php and I"m working on making a very detailed registration form which needs to mesh well with the K2 login addon, and also I'm using CiviCRM in the backend to handle membership logistics.
Additionally - the biggest stumbling block to this project is that I'm using JFusion to link phpBB/Joomla/Wordpress.
Yesterday I spent a few hours trying the traditional method (modifying User.php and adding tables to my DB) however while i was able to change the form front end, after updating the user.php file, my site was nuked.
The issue was so bad that all I know is that I was getting 500 error's on all pages and my host was unable to do anything since the backend was DOA. I was able to restore the site however, thanks to a prior backup, however because of the mishap I'm looking to get a second opinion because I have a feeling the JFusion had something to do with the error.
Here's the link to the original tutorial I was trying to follow. As most of the line numbers were out of sync with my install, I have a feeling I was doing something wrong, but as I had a custom template I thought that it was normal.
http://manchumahara.com/2010/03/18/how-to-add-extra-fields-in-joomla-registration/
Thanks in advance for any assistance,