It is important to have good time keeping on a home network, particularly when receiving Weather Satellite Data. I have made an NTP Server from a Raspberry Pi and a Sure GPS module. I connected TP5 (GPS_Dataout) on the Sure GPS Board to a GPIO port on the Pi, and Gnd to Gnd of course. I used the Python module rpo_gpio_ntp, (link from David Taylor's Site once again) on the Pi running Wheezy Raspian (a form of Debian Linux). All I do is to point the NTP clients at my server, and the computers will all be on the same time.
I now have a very low power device allowing my computers to keep accurate time, without polling the internet all the time. Very effective, and great fun to do.
Using MRTG Multi Router Traffic Grapher I can keep an eye on the performance of the NTP Server.
The Time Offset in microseconds is shown. As can be seen, the error is very small indeed.