I only have one number, so people from work call me from time to time. Though I largely agree - in that case I just have their numbers in my address book copied from the company register, even though they've never called me.
Ah. "Cold call" as in "not in your contacts list." Cold call usually refers to a sales call to someone who you don't have a prior relationship with (i.e. isn't current customer or hasn't requested information).