Here's a quick one to try, I use it at work when getting my Ubuntu computer and Windows 2003 servers to play nice with sharing files.
Go to "Places", then click "Connect to a Server"
Change the publicftp to "windows share"
Put in the other computers IP address and share directory (if needed). Click okay, if you need authentication, the auth box will appear, add your username & password, clear the domain box and click save password forever (only do this in private use, otherwise anyone can dive into the other computer through the share).
The rest is all electrons