[flyingdragon]

What does registering my pin do? Also, will they charge me for doing so?

[dictoresno]

what? what are you talking about? when service books get sent to your phone, you get an email or sms letting you know the registration completed. so if you have a blackberry data plan, you want the device registered on the account.

[dkustec]

No worry for you...
Without data plan registering is not possible...