The hexadecimal 8-digit code used to identify members on the Blackberry Messenger, usually called BBM. This amazing chat service, very popular among teenagers, is one of the few reasons why people use Blackberry's and don't switch over to Android or iPhone. Many teenagers like to post their PIN on Facebook in the place of their workplace on their profile.
"Hey, we should talk sometime. What is your PIN?"
Possible answer one: "Yes, we should. My PIN is ..."
Possible answer two: "Yes we should, but i don't have a Blackberry, I have an iPhone. Do you want my number?"
Answer- "Lucky! How is your iPhone? I'll take your number."