Automatic registration of new users - if the user wants to..

When shopping on Amazon you can check yes to become a member at checkout page. How can this be done in MarketPress?

In MP checkout page (delivery) you enter all information needed (except separate first / last name) to register, and I am able to use 'wp_create_user' to get the user registered. But no email with password is sent do the user. I guess I can take the password i plain text and put it in the confirmation email.. The best place to put the code probably is the 'mp_shipping_process' action hook.

The main problem is that the order is not connected to the user account unless the user is logged in during checkout, so I have to figure out how to automatically log the user into wp - or how to connect the order to the user without logging in..

So.. if anyone else has done something - or have some new angels on how to solve this, please join in..

Espen