I hate user objects, but.....
You can share them ONLY IF the other user has never created user objects. If they have none of their own, you can give the user the UDO file that is related to the universe. If they store it in the right place (the directory where the universe lives), they will have the same ones as you.
Ties is right. If you need to share a user object, get it added to the universe.
Steve Krandel
Symantec