Yes, I'm imagining 1-5 stars with text descriptions to help ratings be consistent, similar to how software like http://mnemosyne-proj.org/features handles ratings.
Other CRM tools I've used will allow you to create groups/categories of contacts and set the recurrence to contact people in that group. You could similarly rate the group instead of individuals. Then the user could re-evaluate based on the group (friends, colleague, family, etc)
You wouldn't put stars on people but on relationships... it's something you can have am effect on, so I wouldn't mind rating it !
Ohhh I see the subtitly. That is an awesome idea. Thanks!