You can find out your PIN by going to Options->Status on BlackBerry devices and Phone->PhoneInfo->HS SN on Palm devices. Enter in your Phone number if you are using a Pocket PC.
Responses are answered in the order they come in. You should receive a response within 24 hours Monday - Friday.
To reach a representative for US Sales or Technical Support contact Sprint at 1-800-639-6111. [9AM to 10PM EST M-F and 9AM to 5PM EST Saturday]