[thelist] moving from 2 authentication systems to 1 unified system?

[morife at ekoile.com]

Hi & thanks for taking a look @ my issue:

I maintain a site that has a store/shopping cart system that I co-wrote
and an open source message board (phpBB) system.

The site has grown more than I ever imagined & with continued growth,
rather than further fragment my users forcing them to have 2 or more
accounts, I’d like to integrate the two systems & move forward under one
unified user account/authentication system.  Another important reason for
the integration is that I’d like to use the unified account as a “user
control panel” where they can monitor things like orders, email
newsletters and the like.

I’ve never done anything like this before.  Can someone point me in the
right direction or offer me some “best practices” or a way of going about
migrating users from the current systems onto the new unified system?
I’ve looked into an API for phpBB, but I wasn’t able to find one – I
really don’t mind branching the codebase (or moving to another forum and
branching that code)

The databases are mysql and the code is written in php running on apache.
I’d really like any ideas or experiences anyone can offer – I realize this
isn’t a trivial issue.

Thanks for the help & your time!

 - m