Is there a 'text or user reference' module? Currently, I'm planning on using a text field for full names (added fields field_profile_full_name and field_profile_partner) on user entities, so that one user can link to another. However, I might not get matching entries in autocomplete (which rules out user references). What I want is this:


A match to text entered in field_profile_partner is found in field_profile_full_name: return/use the text in field_profile_full_name.
A match is not found: use the text the user entered in field_profile_partner, without creating a new user.


I know that a 'text or node reference' module exists for Drupal 6 and 7, but I've been unable to find a module that does the same thing for user references. Does such a module exist or will I have to clone and adapt 'text or node reference'? Can I configure entityreference to give me this functionality?

Note: I know that I could write a custom form and autocomplete page to handle this, but the functionality needs to be on the user account/registration form. If this can be done in hook_form_alter, please provide it as I've had no luck getting that hook to work whenever I implement it on anything.
The Entity reference module will relate any Drupal entities. These include:


Nodes
Users
Taxonomy Terms


So should be perfect for your needs.