The easiest thing to do is plunk down $15 and buy a commercial digital clock with a wwvb receiver built in. Mine are all marketed by Oregon Scientific, but I'm bettin' they're available at Radio Shack.
Assuming by "wall clock" you mean something that you look at and don't really need anything closer than a second...
The next easiest thing to do is plunk down a buck for a garage sale pc and set it's clock to the master clock on your main pc. Just resync it periodically so it stays in sync within the resolution of your display. My PC is hooked into the stereo to play MP3s and has a BIG clock display. Here's the batch file: rem this runs on music at startup to sync things up. rem This sets local time to main system time. net time \\main /SET /YES
Or you can just broadcast the time over your network. I use the mailbox protocol, just because that was all that worked with the OS I had at the time. I'd probably try to use named pipes if I did it again. Have a process running at the destination to catch the time and display it.
Or you can write a basic program to stuff the time out any of the ports. The time is easy. Depending on your OS, accessing the ports may be a hassle. You still need a display.
Having said all that, I find that I never need to know the time more accurately than what my watch says. I keep a stock of "chill pills" for use when I think I might need more resolution. The impulse soon passes ;-) mike