Facebook "Friend Lists" in Drupal.

Goal: To create Facebook-like "Friend List" permissions to allow/deny access to nodes.

A client is requesting a social networking site that has a friend system very similar to Facebook. I have done some investigation on the forums and Drupal chatroom and found that the User Relationships module best fits the sites needs. Users should only be able to see content posted by their friends; User Relationships module has this built in. However, the client has also requested that users should be able to create their own set of user permission groups for more finite control of their content. Allow me to elaborate.

User James has two friends: Jane and Julia. James has created two permissions groups: Friends and Co-workers. Jane is in the co-worker group and Julia is in the friends group. James wishes to post content that ONLY his co-workers can see (i.e. Jane in this case). Each user will be able to setup their own permission groups and thus restrict/allow access to each of these groups (think Facebook friends lists).

What would be the best way to approach this problem? To the best of my knowledge, the User Relationships module is unable to perform this task entirely; it cannot create per-user permission groups. Would a custom module be needed to perform this task? However, using a custom module would involve node access permissions...which would conflict with User Relationship Access module. Do I need to toss the node access portion of the User Relationship module and rebuild that portion into my custom module?

Any help on this matter would be greatly appreciated.