Here is a method to do it without any router…
I ve been using this method to share my sify wireless broadband with another laptop..
1) Install and configure wingate on the server pc
2) Set wingate to run services such as HTTP proxy and SOCKS proxy
3) Now Configure the computers for a LAN connection with static IP.
4) Now on d client machine, u need to configure the HTTP or socks proxy of ur browser to point to the server`s LAN ip.. ( in my case, my clients http proxy was set to 192.168.0.1 and port as 80)
Remember, u need to configure proxy in setings for all the apps u use on d client like yahoo messsenger, download managers , etc