has_many :friends, :include => :befriendee, :conditions => ["users.visible = ?", true]
has_many :tokens, :class_name => "UserToken"
has_many :preferences, :class_name => "UserPreference"
+ has_many :changesets
validates_presence_of :email, :display_name
validates_confirmation_of :email, :message => 'Email addresses must match'