Hi!

Just a little addition to the DCF77 thread: have a look at

 http://www.germany.net/teilnehmer/100/26108/funkuhr/home.htm

It contains a very nice collection of documents regarding radio clock signal
receivers and includes detailed instructions how to build such a receiver
yourself or where you can buy moderately priced receivers for computers.

The page is german language, but an english version is shown if you click on
the US flag in the upper right corner.

Regards,

    Michael Böhnisch