I just talked to the customer support people via the phone number 1-800-866-2453 about the ramifications of suspending a phone line discussed here: http://support.t-mobile.com/docs/DOC-1717
This representative said that billing is not stopped, So the only point of suspending a line if you're just away for a while is to avoid people caling and sending you texts and what not increasing your bill, is that right?