Unregistered's Numbering System

PROBLEM:
I have a forum that unregistered users can post in. Although some choose to change their "guest" name to something other than "Unregistered", most don't, and on busy threads, confusion occurs.

SOLUTION:
In the newreply and newthread files, instead of assigning "Unregistered" to the username of posters who aren't signed in, use "Unregistered" plus a 4 digit random number. This new username doesn't need to be cookied to a user, its just to keep each post unique for reference.

I'm working on this myself, and I think its just required in newreply and newthread, but if someone already has something like this, please post it here.