If both your PC's have network ports on the motherboards then its a case of plugging in the Network Switch (its an 8 port) to the mains and connecting one network lead per PC to it and setting file sharing going. (I can supply the leads too)
There's a sync issue with most of them on there but thats one of the better ones.
This on the other hand was a cool commercial and in sync.
http://www.snotr.com/video/624