Rated 5 out of 5 stars
Love this add-on. It's compatible with thunderbird converstations which is a nice plus (it tiles the pictures vertically at the side of the email windows when converstations add-on is enabled rather than at the top which is I think very appropriate).
Would love to see a feature where I could set priority on which photo is used. i.e. prefer linked-in photo if both linked-in and facebook have photos.
The latest beta version has an ugly UI for you to config which photo can be used in advanced settings.