I'm surprised that networking cable wasn't run with the phone cabling and that they used network RJ45 jacks (8 position) at the wall jacks for phones and not RJ1 (4 position) which make it that much more confusing.
That makes 2 of us. They obviosly weren't considering using the Cat5 for broadband either. They used it instead for standard telephone hookup. I"ll never understand the logic in that.
When I had my walls down for remodel I ran cat5 through the walls and up to my son's room.
Now they can hookup their Xbox without going wireless. Oh and my house wasn't built 2 years ago it was built two centuries ago well actually 1892.