NBTscan is a program for scanning IP networks for NetBIOS name information. It sends NetBIOS status query to each address in supplied range and lists received information in human readable form. For each responded host it lists IP address, NetBIOS computer name, logged-in user name and MAC address.

This program is a successor of a perl script with the same name and does essentially the same thing, being much faster though. NBTscan produces a report like that:

IP address       NetBIOS Name     Server    User             MAC address
------------------------------------------------------------------------------
192.168.1.2      MYCOMPUTER                 JDOE             00-a0-c9-12-34-56
192.168.1.5      WIN98COMP        <server>  RROE             00-a0-c9-78-90-00
192.168.1.123    DPTSERVER        <server>  ADMINISTRATOR    08-00-09-12-34-56

Website: http://www.inetcat.net/software/nbtscan.html