One paper on netcat uses is fine, but two sites in two days exceeds my Recollection Buffer and defaults back to needing a post.
Dean De Beer offered up a paper on Netcat for the Masses which gives some good initial infomation on playing with netcat.
And I found Luke posted even more uses for netcat.
And this one:
http://blog.vulnerableminds.com/2007/07/all-networking-you-could-need-netcat.html
Though Luke’s is a lot more detailed than this one.