How to unlock new 2g iPhone to use as extra phone line?

[California]

Apple replaced my 2g iPhone and it's nice to have it as an iPod touch but i'd like to add an extra phone line to my existing 4g phone contract with AT&T.

They told me I had to have the phone unlocked in order to turn it on?

Never did that before, does anyone know how to get a 2g iPhone usable again in 2012?

 

[rrandyy]

Is it out of contract? If so, call AT&T and ask them to unlock it for you.