Just had a nightmare finding a binary for windows that wasn’t cygwinized… eventually found it here

http://www.hackosis.com/wp-content/uploads/2007/12/nc111nt.zip

[update]

Jon Craton has mirrored this file in case the other link goes down

http://joncraton.org/files/nc111nt.zip

(Cheers

[update 2]

It seems that antivirus programs mark netcat as a threat when actually it is just a useful tool – see conversation and links in comments for details.