Your computer is hooked up to a wire giving it internet service?
Just unplug the cable and hook it up to your PS3, it'll work just fine.
If you're receiving internet via wireless already, I don't know how you'd go about finding the source of it, the modem, and connecting a router to it. Also, if you did that, you'd want to set up a security system for it in order to make sure no one leeches. On top of that, you'll have to check to see what kind of encryption code the PS3 is allowed to work on.








