Not sure if I just missed this feature from awhile ago, but I just noticed that when you hover over a friend’s name on Facebook, you get a pop up similar to what Twitter implemented awhile ago.
Personally I like the way Facebook has implemented this a little more than Twitter, but only because it shows you a little more information about how you are related to the person (ie 16 people in common). I wish that the Twitter pop up gave more information without having to click ‘more’ or the cog button.
I always open a Twitter profile in another tab because to me I care more about what people talk about, not who they are or where they are from. While there is still much to be desired in the Facebook pop up, I feel that it is already slightly useful than Twitter’s pop up as you can easily see mutual friends, ‘like’ companies, send your friend a message, or add someone new as a friend without having to click a cog, or the ‘more’ button.