If it's just down the hall I would just use some Cat 6 cable and wire the PS3. That way you'll always get a nice stable connection all the time and at a faster speed (up to 1000Mb/s depending on your router and ISP).
You can buy 50 feet of cable from
www.monoprice.com for $12, shipping included.
If you're going with my advice, use an insulated staple gun to fasten the wire, T-59, 5/16 inches is recommended or use the plastic cable fasteners they use for RG-6 coaxial. Whatever you do don't put too much pressure on them, these data cables don't like being pinched.