Why would you want it to be someone's Facebook picture. Half the idiots I know on Facebook change their pictures every two days and usually put up pictures of monkeys or cartoon characters. When my phone rings, I want to see a familiar face. One I put there. Assign your own photos of people you know using Gmail's contact list (on your computer) and sync. They will remain consistent instead of pulling the latest gag shot from Facebook or Google+. Having my phone ring while meeting with my boss and having my buddy's latest shot of himself dressed as a transvestite for Halloween showing on the screen doesn't usually go over well.