Yeah, it's a redundancy when you realize that ATM already has the word "machine" in the acronym, but people say "machine" anyway. PIN works the same way. Still, my favorite redundancy I hear all the time is "Where are you located at?" There are three words in that sentence that mean the same thing, and two can be dropped. "Where are you?" is sufficient. This comic is from Zack Weinersmith at Saturday Morning Breakfast Cereal.