I must be old-fashioned, I use a good 'ol
proxy server. Slapped some parts together, and installed Sygate (Great software, IMO). That goes to a Netgear 10/100 hub. My PC, my wife's PC, a test cable, and an uplink cable to the second floor plug in also. That uplink cable plugs into a 5 port cheapo hub, serving the 3 PC's upstairs. It was a bear running it thru the subfloor..
Running cable to my wife's PC was a bitch. It's in the formal living room, it has cathedral ceilings, and no where to run a cable down a wall. I ended up using a HUGE masonry bit, silicone, and some decorative wire guide. We had a 2nd phone line added to the same room, Telco installer did the same thing.
It is nice to feed 5-6 computers broadband speed for $39.95.