Nbtscan : Gathers NetBIOS info from Windows networks
NBTscan is a program for scanning IP networks for NetBIOS name information (similar to what the Windows nbtstat tool provides against single hosts). It sends a NetBIOS status query to each address in a 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. The original nbtscan was written by Alla Bezroutchko. Steve Friedl has written an alternate implementation.