Quote Originally Posted by Antonio1986 View Post
What do I say when I call a stranger?

"Good afternoon Mr. XCZ"

(I) "Am I disturbing?"
or
"This is the right time to speak with you?"
or
"Are you occupied? Do you want me to call you later?"


or
Any other viarant you russians used when you do phone-calls to strangers.

(II) I am speaking on behalf of Mr. UYZ
I. Добрый день, вас беспокоит Владимир Иванов. У вас найдется минута свободного времени?
(Мы можем поговорить? Это не займет много времени) - say this even if is not true and will take some time

II. Я говорю от имени Бориса Николаевича.

P.S. Never, never use any mr\comrade\товарищ\гражданин. There is simply no appropriate verbal honorifics these days. Sometimes "господин" may be used, though.

P.P.S. Check http://masterrussian.net/f21/%D0%BD%...3%D0%B5-21792/