Not Free but One of Best apps I can suggest:
http://www.youngzsoft.net/cc-get-mac-address/index.html
and
http://www.purenetworks.com/product

i found this on majorgeeks.com

it might help those with the error posts of their networks having lost songs that monkey seems to have lost and can't find on the network servers?

http://www.majorgeeks.com/Lansweeper_d5981.html 8) hope it helps

roving cowboy / keith hall / monkey hi fi