VNC Server IP & VNC Password? Windows Vista

I've downloaded this application for my iPhone 3G which would allow me to connect to my laptop but it asks for the VNC Server IP address of my computer and the VNC password.

I did a ipconfig/ all command in cmd but it returned two addresses:
IPv4 Address: 192.168.1.66(Preferred)

and Default Gateway/ DHCP Server: 192.168.1.254

Which one of these should I use?

Also, what is this VNC password? Where can I get it?

The application is called Real VNC: http://www.realvnc.com/ if anyone's heard of it and knows how I could get it to work, I'd greatly appreciate some assistance.