This module adds the ability to reference non-existing (new) nodes right from nodereference field when You're adding or editing the node.
It's recommended to use this module with a Form restore module. It simplifies the workflow and enables support for multi-step chained nodes creation - if the content type of new node have nodereference fields it is possible to add and reference from it and so on (up to 10 steps now supported).
Thanks to Form restore, after submitting of new node You will be returned to the previous (still not submitted) form with all values You have filled before and (of coarse) with just added node in the field where 'Add new...' button has been pressed.
Note #1: This module requires content.module, nodereference.module and form_restore.module
Note #3: This is my first project so please feel free to point me to my mistakes, I'll fix it as soon as possible.