A friend and I are trying to play Minecraft SMP, and our computers are on the same router. I'm hosting the world, so what do I need to type for the "IP address" field? There's no need to portforward, since we're on the same router. But after looking up my IP address and trying to use that number, I got a message saying "Can't connect..." So, considering the fact that we're on the same router, what am I supposed to do?

Any help with this would be greatly appreciated.