You can also access the same information via the web by using www.free411.com. 

Cost based Directory Assistance:

To reach directory assistance from a campus phone, Dial 9 + 1411.  After entering a valid 6 digit PBN, follow the automated prompts.  To use this directory assistance you will need to use your long distance Personal Billing Number (PBN).  Directory assistance costs $0.95 per call.

You will need to make sure to have a paper and pen handy.  Your call will not be automatically connected to the number.