Blackberry PIN to PIN

[racmac]

Please explain simply how i do this?

If i have a friend on blackberry do i need to get their pin?

Where do i put it?
I have a blackberry curve 8520
thanks

its so that you can send a boackberry message for free. like a text message. you can store it in their contacts page. or go to Blackberry messenger and press the menu button, you get an option that says add contact. you enter their pin in there.