Watson, ( STRICTLY EXPERIMENTAL PURPOSES ONLY ) my strong suggestion would be that you build an asterisk and publish it on the net. Since all your family have laptops and a basic net connection, within the asterisk create sip extensions.

 

Example :

 

Watson ext  : 0001 ( nairobi )

Watson Dad ext : 0002 ( nyahururu )

Watson Brother ext : 0003 ( mombasa )

 

Then download simple sip clients on each laptop/desktop plus headphones. Once they connect on the net, launch the sip clients and BOOM! registered. To place a call within the same group : tell the person whom you are calling to go online and launch softphone. Then watson calling his dad dials 0002 on his soft sip phone and connects.. :-)