We purchased 1000 feet of category-5 wiring from Greybar, along with a bunch of RJ-45 ethernet jacks and RJ-11 phone jacks. Most of the house is now wired for ethernet. We also installed an audio bus, so that any audio source in the house could drive multiple amplifiers. We made custom cables that convert the four wires in an RJ-11 connector to left and right stereo audio.
The house network is connected to the cable modem via a cheapo Intel box running RedHat Linux. This box is our router, as well as our shop development station for the avionics for Kevin's Dragonfly.
We're pretty loaded with computers. Max uses an Intel box running NT, as well as one of the new whizzy blue G3 mini-towers. Kevin does development using the Linux box. Kym has a PowerMac G3 that she uses as a recording studio along with her Roland A-90/EX keyboard and Akai S-6000 sampler. Dave has a Powerbook, and Becky has a PC of some sort, mainly used for playing games. They all use DHCP to get IP addresses from the router, and we do IP masquerading behind our one static IP address (24.5.200.128).
The house has been wired for extensive X10 home automation. The bathrooms and the entryway use motion-sensors to turn the lights on and off. The entryway sensor only turns the light on if it's dark. All of the lights in the house under X10 control are set to automatically turn off at 10 AM and 1 AM, in case any lights were left on. We can also use the X10 stuff to randomly turn the lights on and off when we're away, though that's not yet set up. I'm not sure how long it's going to take for our reduced electric bills to pay for the $500 worth of X10 stuff we bought -- probably will be quite a while. It's still pretty cool, though.
Our entertainment center is slowly improving. We have a 32" TV, SVHS VCR, DVD, some fancy speakers that Beck owns, and a Sony surround-sound tuner/amp. We have DSS instead of cable (although we physically have TCI's cable for the cable-modem). Rus installed some nice Bose outdoor speakers on the deck, but since he moved out, once he remembers that he owns 'em he'll probably come try to take 'em back.
And if you're a thief and reading this, be warned we have some whizzy alarm system, plus three vicious attack cats.