Ayatollah Ali Khamenei apparently has signed up for his own page, complete with appropriately artistic photograph. Don't know if he has poked anyone yet or posted a status update, such as "Wishing Mahmoud Would Get His Cabinet in Order", but he does have 20 friends.
11 August 2009, 1735 GMT: Mir Hossein Mousavi is not yet a friend of Ayatollah Ali Khamenei. Are you?
1810 GMT: Ayatollah Khamenei reportedly displeased that he shares his Facebook page with ads for "Prostate Treatment" and "Betfair Arcade".