Ok if my friend has a router set up in his living room, and only 1 line going to his room, can i use another router in his room to split his line in tow so we can LAN out PS3's?
You can use another router but use it as a switch. Turn off dhcp on it. change the ip of the second router to something outside of the dhcp range of the first router that will be your dhcp server. The easiest way is to use a switch if you have one lying around. They are cheap. If it is another persons router that will be taking it home it would be a pain to make all of the changes you need just to change it back for your friend to have it work at his home as a router.