How could I creat an Arduino TCP server

Thanks to your great lib for Arduino, I have tested TCP client and it's working well!

But, How to build a TCP server on arduino? (e.g ip "192.168.1.100" and port "2000")
I want to use my laptop as a client to send some chars to Arduino Server

here is the wifi shield(RN171) which I used
http://www.seeedstudio.com/depot/wifi-shield-p-1220.html

Thank you!
