Hey. Here's what I'm trying to do. I want to connect both my PS3 and laptop with an ethernet switch and use online multiplayer and the internet on my computer at the same time. I live in a dorm that has an ethernet plug in the wall (no router). Is this possible to do? Any other options? Thanks very much!

Yeah, just plug in a switch or a hub into the port and connect your stuff to it. Keep in mind that they may limit the amount of MAC addresses that the port learns, which means that you'll only be able to use one of the X number of devices that you plug into your switch...but it's still worth it to give it a shot, I don't know how restricted dorms are.