Me and my friend are both behind routers and would like to play multiplayer games together without having to access a central server. The problem is that we have no idea what ip address to put in when asked for it. My router gives me an effective IP of 192.168.0.4 and his is 192.168.0.103 We know the actual IP of the routers as well but I don't feel comfortable posting that here. Does anyone have any idea how we could connect our PCs together?

To get your IP address, go to http://www.whatismyip.com/

I should also mention that since both of you are behind firewalls, you may not be able to connect to each other. Consult the instuctions for your game and router to open the needed ports.