I have been thinking about this for a while and thinking it would be a good unique sort of friends list.
Ok, it would go sort of like this
Mental Link - Allows you to talk directly to that person no matter where they are, be able to sense them while they are close (within 50 metres or so) by seeing them through walls and such.
Spiritual Link - Allows you to see your friends health and you are able to tell exactly where they are and see them through walls, although no direct verbal contact can be made with this person unless you are within games default talking radius of eachother.
You may only have one of those links with each person.
There are still some things that still need a little fine tuning as in there is not much point in the spiritual link being able to sense where they are no matter what as with the mental link you could just ask where they are. This still would be quite a good way of dividing your adventuring buddies from your social buddies.
I also thought up some messages for when your friend logs in/out
Spiritual
Log in - A fimiliar feeling rises inside of you
Log out - You feel divided by an unexplainable force
Mental
Log in - A fimiliar presence grows in your mind
Log out - Shadow moves through your mind and quickly passes
All types of comments and criticism are welcome