An idea is that could join commentaries on the contacts, commentaries that only would be seen by ourself.
It is in the habit of happening to me is that there is information of the contact that I forget and always is good to have them.
I think this is gonna be useful for people who talk with different persons and never know they very well.

I hope every understand my idea and my english.

Ernii(I'm from Argentina)

You can already attach data to a contact using 'Edit Contact' in the Contact List